Let me tell you a story about a boy. When he was young, he watched a television program known as Dr. Who. He loved the show, and watched it religiously. He decided then that he wanted to be like his hero, the fifth incarnation of the Doctor.
And so, he began acting. Through years of work, he finally was able to achieve his dream, and he became the Tenth Doctor [http://www.imdb.com/name/nm0855039/].[footnote]That's one.[/footnote]
During his run as the Doctor, he played in a certain episode [http://en.wikipedia.org/wiki/The_Doctor%27s_Daughter] with Georgia Moffett, the daughter of the Fifth Doctor's actor.[footnote]That's two.[/footnote] In that episode, Georgia played Jenny, a partial clone of the Doctor[footnote]That's three.[/footnote] (who is referred to as his daughter).
Several years later, they had a child and were married.
That child's name is Olive Tennant.
And she is the ultimate Time Lord Baby.[footnote]See one, two and three.[/footnote]
She deserves to be the first female Doctor.
....Wait, you asked for the 12th Doctor specifically? Then just let me steal this:
PurpleLeafRave said:
Hugh Laurie!
C'mon! He'd be a great Doctor.