"Elizabeth, what's wrong?" Sherlock rapt his fist against the bathroom door again, his eyebrows knitted together, eyes wide, and mouth parted. A sob came from inside, which did nothing to calm down the increasingly frantic father outside.
"Elizabeth?!" Sherlock nearly shouted again. Suddenly the front door to the flat opened and John walked in, carrying large brown bags of groceries under each arm. John didn't even have time to set the bags down before Sherlock rushed him and twisted his fists into John's jacket.
"John something's wrong with Elizabeth!" the panic in Sherlock's voice was poorly masked. John felt his own blood chill at the terror on Sherlock's face. Seeing the man who was usually so calm and collected in this new state of alarm had John unceremoniously dropping the bags on the floor and sprinting to the bathroom where Elizabeth had locked herself in.

"Liz?" John tried the handle to no avail. "Elizabeth, are you alright?" John asked the loud sobbing.

"NO!" I shaking response was shouted back at him through the door.

"Lizzy, love… what's wrong?" John tried to keep his voice calm, but Sherlock's antsy pacing was setting his own nerves on edge. John flashed a glare at Sherlock and waved his arm at the man to get him to stop his apparent marathon training.

"I'm dying, Dad!" The wretched, quivering voice managed to sob out. John knew their daughter was not one for being dramatic, so either she was seriously injured, or the thought the was.

"Love, open the door please. I cant very well help you if I'm on this side."

A hiccup sounded from the other side and there was silence for a few moments.

"That is t-true…. " John could here her working out the logical solution, and sure enough, after a few more moments, the lock un-clicked. John cautiously opened the door, Sherlock already standing flush against his back trying to peer into the bathroom over him. John elbowed him in the gut and shoved him back a few paces before opening the door.

The sight before him made him want to laugh, cry, and exhale in tremendous relief. All of which he did not do for the sake of his daughter. She was kneeling by the toilet, clutching her abdomen. There was blood in the toilet bowl and on the towel she was collapsed on. Sherlock, bless that stupid genius, saw the blood and was about to question what had happened but John whacked him softly on the shoulder, telling him to shut up. John went over and knelt by his scared daughter.

"Elizabeth, have you heard any of the other girl at school talk about getting their period?" John's hesitation before his final word was minute but easily picked up by both the others. John glance back at Sherlock who looked possibly more mortified than before. John rolled his eyes and turned back to their daughter.

"Y-yes. No…. I don't remember…" She scrunched her face up and turned to John with pleading eyes. "Dad am I going to die?" John allowed himself to smile a bit. He put his hand on her back and rubbed in circles .

"No love, you're perfectly fine. Very healthy, actually." John's years as a doctor had exposed him to this enough. He wasn't particularly comfortable explaining it to his daughter though. Maybe they could call Irene to- No. Definitely not Irene. Maybe Molly. Yes, Molly was a much better option. "Lizzy, this is your period. It means your growing up and becoming a woman." John's own face looked slightly pained as he said that, but he smiled anyway. Sherlock was just vulturing over him, trying to listen to any explanation John was giving.

"Why is there blood?" Liz had calmed down tremendously after hearing her father, the doctor, explain that she wasn't on the brink of death.

"It's… ah…" John was at a loss for how to explain this without re-freaking her out. Your internal organ is shredding it's internal lining to clean itself and prepare for a potential baby. Just didn't seem like it would do much good at the moment. "It's your body trying to clean itself out. How about you clean yourself up and then come out for some biscuits and we'll explain it then, alright?"

Elizabeth studied his face for any trace of lying, a skill Sherlock had taught her. Then she nodded and John stood up, nearly knocking into the hunched over Sherlock. John ushered his husband out of the bathroom and shut the door behind him. They both lingered outside the door till they heard the shower turn on. Finally exhaling, John looked at Sherlock and they mutually understood they were in for a lovely evening.