Zalia is certainly feminine to me! It looks distinguished, almost regal - but it's a little bit heavy in the sense that I think of a mature, stylish grown woman in her late 30s to early 40s - kind of like I do with
Zelda. In other words, I can't really mentally picture it on a little girl or a baby. But that's just the impression that I personally have: Zalia may well suit your girl despite her young age. ;)
Oh, and I just thought of
Ollie as well. Yes, I know you're looking for something that ends in -a - but I couldn't pass up mentioning this one. It's usually used as a nickname for
Oliver, but it could be so cute on a little girl! But again, that's just my opinion. :)