I've never seen
Talitha before, but I'd say TAL-i-thə like it has listed here. It has a neat meaning, I see, but I don't like the look or sound of it at all. I would probably avoid using
Lolita if I'd used
Talitha, but I don't think they're so similar it would be horrible to have two sisters with those names.
I wouldn't say
Annabel is getting too common here, but I think it has potential to get quite common. I have no idea what other people would assume... probably
Annabelle because they wouldn't know
Annabel was a possibility and they'd just do
Anna +
Belle. But I prefer
Annabel, it's much less frilly. I pronounce them both the same.