Disclaimer: I am giving my opinions as a [name_u]Brit[/name_u] who has never been to [name_u]America[/name_u], so dont really know how they will go down in [name_u]America[/name_u] (though I imagine it would be different in various states)
[name_u]Alix[/name_u] is a nice name. You/she would likely find that most people spell it [name_u]Alex[/name_u], without checking the spelling, since it’s far more common. I know a girl called [name_u]Alix[/name_u], who’s 15. While I think that [name_u]Alix[/name_u] looks nicer than [name_u]Alex[/name_u], i would generally avoid names that will be misspelled over 90% of the time.
[name_f]Alba[/name_f] is nice. It is an old name, but vintage names are quite popular in the UK at the moment. I have never heard of anyone called [name_f]Alba[/name_f] - I think it’s definitely passed the negative ‘grandmother’ name, and into the ‘great grandmother’ names, which are quite common for revival. [name_f]Alba[/name_f] reminds me of other vintage names like [name_f]Clara[/name_f], [name_f]Ada[/name_f] and [name_f]Olive[/name_f]. This would be my preference.