Lol! I had the PERFECT name... but it's already on your short list....
Sam(antha). I think the name Sam or Sammy for a girl is super cute.
Have you thought about waiting for the little guy/gal to pop out and TELL you their name? Like, maybe it will be super obvious.
You have some really good choices already, though I understand not yet feeling the right one.
And I really like Ashlee for a boy, but that no doubt comes from me reading/watching Gone With the Wind.
Charlie for a girl!? That's cute too! Then, you'd have to compromise with an old-school name like Charlotte.
Choosing a name with several possible nicknames may be good too.
Oi!
Good luck!