I personally prefer
Adeline over
Adelina, if I'm to be honest, but I do find
Adelina to be very beautiful itself.
You might want to think about, also, the double A if you choose
Adelina --
Adelina Aleksandra. It just depends on whether or not you find that bothersome.
Both are very beautiful names - great choices! I like
Polina a lot as well, but I'm tempted to say "Poe-lee-na" right off. I like the flow of
Polina Aleksandra.
Nn's for
Polina:
Po (pronounced Poe)
Olin/ Olina?
Poli (
Polly)
Lin
Nn's for
Adelina:
Adel/e
Adela (as it is a form of
Adela.)
Del
LinAddieAdeli (aay-deh-lee?)
Hope I could be of some assistance!