I think less than 20 weeks you still can, but google it, you'll find out for sure on that front.
Really not sure what to say as it's a really tough one. All I can do is give my opinion and if it were me, I would want to know. You might not be able to change your W mind, but if it were yours, you should have the right to at least discuss it with her (IMO).
Thing is, I would of thought you would have seen info, websites visited or numbers on the cell bill (I'm sure you said you'd done the detective work), so could be completely wrong.
Whre is D2 on Sat morning ? as if she if with W, she might be where she is. Maybe her Mum has a private app and needs your W there by 8 to drive her somewhere