This isn't polish, but (...)
Most names in Poland aren't Polish, they are either Latin, Greek or Hebrew/Arameic (from Bible), there's a small group of names with old Slavic roots, but mostly for men, I guess.
what about Alessa or Alessandra?
And in Polish it would be just Alek
Quite popular (I think that the male version Aleksander
is less common, but I may be wrong). The most common diminuitive for Aleksandra is Ola