Author's Note: Hey everyone. Thanks for the awesome reviews last chapter. It means a lot me when such an important chapter goes down so well. I was really happy with all the feedback. This chapter is quite short but it's good in my opinion. Also I am insanely busy with assignments and I'll need to take a few days to focus on them but I'll explain at the end. Please read, review, and enjoy!

Disclaimer: Clearly I don't own Sherlock. The show is the baby of Steven Moffat and Mark Gatiss, while Sherlock Holmes itself is the creation of Arthur Conan Doyle.

The First Time Margot Smiled?

Sherlock came over to visit Margot. Now that might seem like a lovely and sweet thing; an uncle coming to visit his niece. You might need to be reminded that this was Sherlock Holmes we were talking about and he did nothing normal.

First of all he did not tell the new parents with fussy baby that he was visiting or what time he was visiting. Sherlock turned up in the early evening and, of course, let himself into the house somehow getting around security. Anthea and Mycroft might not have noticed his entrance had they not been in the kitchen trying to find something – anything other than leftover takeaway to heat up – to eat. If Anthea had more energy she would have told him off. Instead she rolled her eyes and sighed. Mycroft was way too used to it to even pretend to argue. In fact, he greeted him quite nicely. It made Anthea roll her eyes even harder.

The second sign that this was a strange Sherlock visit and not a normal uncle visiting his niece was his first interaction with Margot. She had been awake so Anthea abandoned the quest for food and went to get the baby for Sherlock. Immediately he outstretched his arms to hold her which is, yes, sweet. So Anthea passed her over. He smiled at her lovingly and there was no doubt that at least that was sincere. He bounced Margot up and down in his arms and the frowned. His sky blue eyes fell onto Anthea.

"She has put on weight, which is good, but she's still small for her age." He said. Anthea gawked. He had been weighing her? Ridiculous. She looked at Mycroft and he did not seem surprised at all, in fact he appeared quite contended. He had not only expected this but was completely cool with it. "You need to feed her more." Sherlock said flatly. Anthea scoffed.

"I am feeding her." Anthea defended, folding her arms across her chest. "You try breast feeding a fussy baby. Do you know how often you have to feed preemies?"

"I do." He answered. Anthea glared at him.

"It's harder in practice than theory, brother-mine." Mycroft was the peacemaker, still in the kitchen. "An increase at all is a good sign." Sherlock scowled and turned around to face Mycroft while keeping Margot sturdy in his arms.

"What? You decide to stay and suddenly you're the most understanding father the world has ever seen?" He accused his brother but the malice from years ago wasn't there. Actually Mycroft smiled and chuckled.

"No, and that's precisely why I know it's harder than theory." He hummed. "As it turns out we may actually have to forgive Mummy and Father for some of their more reasonable mistakes." Sherlock laughed in his throat.

"Like either of us are capable of that." He said.

"I know." Mycroft said. "It was merely an observation." Anthea sighed and rubbed her head. Margot was never getting a sibling if they turned out like these two, or worse. Not like Mycroft would want extra children anyway.

That's what the rest of the day was and to Anthea it was absolutely ridiculous. Sherlock and Mycroft took it very seriously and Mycroft looked quite smug about the whole thing. Anthea just took the opportunity to lie on the couch and watch this unfold.

Sherlock poked Margot's hand and she clenched his finger. Sherlock looked at Mycroft, Mycroft raised his eyebrows expectantly, and Sherlock nodded.

"Good." The younger Holmes brother practically chewed on the word.

Sherlock asked for a toy. Mycroft handed him Patches because Patches was always near where Margot was as if by magic. Sherlock carefully placed Margot on a blanket on the floor and moved the patchwork teddy in front of her from left to right. He watched carefully as her deep blue eyes watched the teddy back and forward with interest. She cooed at it.

"The brain appears to be developing nicely." Sherlock noted.

"Naturally." It was the smuggest Anthea had ever heard Mycroft. Mycroft was still smiling proudly when Sherlock walked over to where Anthea was. She gave him a bored expression which he returned before turning his scrutiny to the baby. Suddenly he clapped. Margot lolled her head to look over, surprised.

"Good." Sherlock hummed.

"You don't think I've tried that?" Mycroft sighed.

"You have?" Anthea quirked an eyebrow at him. He raised his eyebrows at Anthea. Sherlock, ignoring this, returned to Mycroft's side. Mycroft looked at him expectantly.

"She's developing exceedingly well for a premature baby." He said, fiddling with his jacket to neaten it. Mycroft's eyes were all but shining with pride.

"I told you." The eldest genius hummed.

"Yes, but one can't trust father's – they tend to exaggerate." Sherlock replied. "Father thinks you're smarter than you are."

"I'm smarter than you." Mycroft quipped.

"Yes, but you're not the smartest, are you?" Sherlock looked his brother dead in the eye. For a second Anthea thought this was a year or two ago and that a petty sniping competition was about to begin but then both geniuses smiled at each other.

"I think you should be happy, brother mine, that you don't have two siblings that need institutionalising." Mycroft hummed.

"As should you be." Sherlock answer.

"Don't I?" Mycroft quirked an eyebrow. Smirking, Sherlock rolled his sky blue eyes. Anthea was watching Margot on her blanket to make sure she was safe rather than deal with these two walking and talking children.

"That's how you speak to your baby brother?" He crouched down near Margot and scratched her tummy like she was a dog, or a cat, or something. "No wonder you doubt your parenting skills." He pulled an exaggerated look at Margot at her father's expensive. It was like saying 'the nerve of this guy'. Mycroft didn't appear to have an answer prepared for this, despite the light hearted many of it. Lucky for him, Margot did have an answer. She made a noise and smiled at Sherlock.

Sherlock stood up and backed away.

"Did she just smile at me?" Sherlock asked. This time his attention was drawn to Anthea. Anthea, laying on the couch, shrugged with the shoulder she wasn't resting on.

"She does that." She said.

"It's a reflex until a certain time." Mycroft elaborated. Sherlock's eyes flickered over to Mycroft.

"No, but that appeared deliberate. It was in response to my expression." The detective nattered. Mycroft and Anthea looked at each other. Mycroft took a long and deep breath. He scratched the side of his nose.

"I suppose it could have been her first intentional smile but given that she's premature I'd say that would be awfully quick." Mycroft was stuck between placating his brother and logic. Sherlock nodded and hummed a yes.

"And weren't we all just discussing her remarkable development?" He asked, looking between Anthea and Mycroft.

"Don't ask me," Anthea muttered. "You two were talking, I was trying to stay awake." Mycroft offered her a sympathetic look but was soon side-tracked by his expectant brother. Mycroft pursed and the pouted his lips. He tilted his head to the side, almost shook it, and then nodded.

"I suppose we were, yes." He answered.

"Then this could be a real smile." Sherlock said. Mycroft looked at Anthea, silently pleading for assistant. Anthea, with an exhausted expression, nodded. Mycroft took the hint.

"It could be." Mycroft nodded very slowly.

Sherlock's full attention went immediately to Margot. He silently asked Anthea if he could pick her up again and she let him. He held her close to his chest – the practice with Rosie clearly showing.

"My niece is most definitely smart." He said proudly. "She already likes me the best." Mycroft and Anthea had matching bemused expressions – although both of them were secretly enjoying this.

"She likes you more than her own mother?" Mycroft questioned, an eyebrow raised to the roof.

"Why else would she save her first smile for Uncle Sherlock?" He retorted. Anthea looked at Mycroft. Mycroft met the gaze and sighed.

Whatever, it was cute. It made Sherlock happy and it built up Margot's family bonds. A happy Sherlock was a relatively calm Sherlock, and close bonds for Margot meant more happiness for her. It was okay. This was a part of being a parent, a brother, and…

What was Anthea's relationship to Sherlock now?

He wasn't her brother-in-law but he was so much more than just her kid's uncle.

He was Sherlock. That was good enough, she guessed.

"Anthea, dear." Mycroft spoke later that night. Mycroft was reading and Anthea had been reading until she dozed off. His voice had stirred her out of her light slumber.

"Mm, yeah?" She asked, blinking herself awake. She picked up her phone to make sure she hadn't missed any feedings or anything. It had been ten minutes. She didn't know whether to be relieved or upset.

"Earlier, with Sherlock…" Mycroft begun. Anthea put her phone down and put her attention on Mycroft. She nodded for him to continue. "I am about seventy percent sure that was just a reflex smile." He said. Anthea sniffed a laugh through her nose.

"I know." She said. "I just thought we'd let him think he had the first smile." Mycroft closed his book. He placed his hand softly on top of Anthea's.

"Thank you." He said. She shrugged nonchalantly.

"It was cute." She said. Mycroft took a breath.

"It was… something." He said. Anthea turned her hand to hold his back.

Author's Note: So it was short… but I thought it was cute. What did you think? Let me know. Thanks to our guest reviewers; Guests x3, Enola, Observant Potato, and AbleFoxAlpha. Thanks to all my readers – you mean a lot to me. Which is why I'm hoping you don't mind if it takes me 10 days to update again. I have multiple assignment less than a week apart and I just need to focus on them for a few days. The good news is there's only those three left and then I'll just have exams to study for. I'm sorry it's been a bit of a mess lately but I try to keep it as regular as possible. Thanks guys!