The day that Rose gives birth ends up like most of her life now is - extremely complicated and very far from plan.
It's only because of Chris that she's not hunting an alien when she goes into labour, because he made her stop working actively for Torchwood after four months (prior to that he hovered over her until Rose snapped, multiple times).
Instead she's catching up on some of her paperwork, the stuff she refuses to do when there's running to do and lives to save. It's still not interesting.
She goes into labour and it's just her luck that men that can handle an alien invasion go into hysterics at the sight of their colleague about to give birth. Luckily Torchwood has a medical bay, even if she walks three quarters of the way there herself before Jake stops having a panic attack.
She gives birth to a daughter with a frazzled Chris at her side and together they welcome Donna Sarah into the world. Donna for the aunt she would never know and Sarah for the friend who had recently passed in this world.
And then Chris pouts and looks ready to throw a tantrum.
Rose just laughs.
How like their daughter to be ginger.