A/N: This is bad, and for that I apologize. It's been a while since I've written them, and I still don't think I really nailed their personalities...
Enjoy anyway. :)
Jackie stares at the pair and wonders just how they can complement each other so well. Toss the Doctor with anyone else, and his rambling notions will have him in an asylum before he can blink. And Lord knows she loves her daughter, but years traveling space and time has made Rose just as impossible.
They're arguing, obviously, that good-natured banter they don't realize is a step short of snogging. Something about an all-female race and the sheer semantics of it, she's managed to gather. Jackie sits in the corner watching them because even though they intruded on her, they haven't seemed to realize she's still sitting there.
"It just doesn't make sense, Doctor," Rose exclaims, whirling on her heel and folding her arms. He straightens but doesn't step back, eyes alight with the excitement of a good debate. "How can the Bulmesians reproduce? And if you say cloning, you've just lost the argument, because that's entirely beside the point."
The Doctor is amused, Jackie can tell, but he pretends to be indignant nonetheless, folding his arms and narrowing his eyes. "It's not cloning. It's parthenogenesis. Look, even your planet has species that—"
"Oh, now you're just makin' up words," Rose says with an exaggerated roll of her eyes. She peers past the Doctor with a wry expression. "D'you believe him, mum?"
"Now don't bring me into this," Jackie says. She goes back to flipping through her cookbook; cooking seems like something a good housewife should do, even ones who can afford a full-time chef, and she's willing to pretend to try. Rose shakes her head dismissively and returns her attention to the Doctor. Jackie scans the ingredients of pumpkin pie and keeps listening.
"Making up—" the Doctor chokes, now genuinely indignant. "It's real—"
Rose cuts him off again, her lips tilting in the barest of grins, "You're sayin' I've been to fifty-six different planets and seven galaxies and two dimensions and during that whole time, you never thought to mention the reproductive cycle of an entirely female race?"
"Forgive me if the topic never arose," he drawls, cutting the distance between them in half. "But you, Rose Tyler, still have so much to learn."
She leans forward the rest of the way. Their noses almost touch, and she says, "Explain it to me, then."
Jackie's forgotten her cookbook by now, watching them unabashed. This is better than daytime telly.
"Parthenogenesis," the Doctor begins, his voice dropping as he stares into her eyes, "doesn't require fertilization. The mother does all the work herself, which is precisely how the Bulmesians—"
"So the kid is a copy of the mum," Rose interrupts.
"Then the kid's a clone."
The Doctor wrinkles his nose, but Rose looks smugly triumphant.
"I told you, Doctor, you can't count clones. It's hardly reproducing if everyone's a carbon copy, y'know?" she grins, her tongue sticking between her teeth, and flits off down the hallway. The Doctor huffs in exasperation and follows.
"The very definition of reproduction…" he says, until Jackie can't hear him at all.
She rolls her eyes at the doorway and says, "Oh, honestly."
Maybe she will attempt the pumpkin pie tonight.