A/n: This is my first fanfic in a long time, and my first Doctor Who fanfic, so be gentle. This started as a Rose introspective-y thing, but morphed into something completly different. So, as of now, this is a reflection on the Doctor's track record as a parent. Spoilers for "The Doctor's Daughter."
She looks like Rose.
That was his first thought, as he saw Jenny, his daughter in none of the ways that mattered, and his hearts leapt at the thought. The idea that some part of her remained in him, to be reconstituted like this made him infinitesimally happy. And sad. Sad too.
Then he looked again, and the happiness faded. No, Jenny looked more like his fifth self then Rose. So she was just his after all.
Only she wasn't. He couldn't hear her in his head. He had checked- even if she did have Gallifreyan DNA, she wasn't a Time Lady. She had never looked into the Schism; she had never been to the Citadel or the Academy. He was still alone.
And so what if she was his DNA? That didn't make her his daughter- just his offspring.
He was reminded of his first child- a little boy. Also not his son- the Time Lords had decided to take his DNA and loom it with that of a Time Lady's. He never found out who- Rassilon, he had never even met his son.
He had tried to make up for it- with Susan. Especially after they had passed over her for the Academy, just because she had a little human DNA floating around, even though she had all the attributes. Her father hadn't tried to fight it like his father had, so she had been condemned to a life of normalcy before she even had a choice.
So, he'd done what every responsible Grandfather would have- he scooped her up and showed her the wonders of time and space…
Only to drop her off on 20th century Earth, with some guy she had a crush on. To his credit, he had gone back to see her once or twice- even brought her back to Gallifrey after her regeneration. Traveling in the TARDIS had made her a Time Lady, with all the background atron he had had.
Now she was gone too.
Looking at Jenny just brought all of that back.
But now you have a chance- to do what you neglected to do with your son, to do what you did with Susan. You don't have to be alone.
Rose didn't want him to be alone. Perhaps realizing that she didn't share anything with Rose- except that adventurous and curious spirit- had made him cold towards her. That wasn't fair; to blame her for something she had no control over. And he could teach Jenny to be a proper Time Lady, take her traveling and such.
He didn't have to be alone, he realized, despite the quite obvious fact that Martha and Donna were here with him, he didn't have to be The Last of the Time Lords anymore, as Jenny screamed about making her own choices- running at the mouth like this incarnation always does.
She was his daughter, he decided as he hugged her back. In everyway that mattered.