I finally got around to watching last Monday's episode of HIMYM: Unpause and I think that I have figured out the way the writers are going with the name of the mother. THIS IS A POSSIBLE SPOILER, please stop reading if your one of those people.
Are you still here? Great, here we go. In the latest episode we were told the name of Ted's kids, Penny and Luke, Ted has said multiple times on the show that he wants to name his kids Luke and Leia. but maybe the reason why the daughter's name isn't Leia is because.... Leia is the mother's name! I truly think that I solved the big mystery. Please someone out there prove me wrong so I can move on and be surprised like the rest of you.