If you google the name Sana you find that they are more commonly given in Arabic and Hindi countries and also used in Japan, with different meanings I'll guess.
Don't think Sana is from any of this countries/ethnicities but I can be mistaken. But if you add "Croatia" to the search you find that isn't a common Croatian name nowadays and the probable use of the name is because a river named Sana in the region, Bosnia mostly but touches a bit of the Croatia frontier, and that river name derives from the latin word Sano/Sanus that means healing/purity/healthy, we Portuguese use that word with that meaning but derived to "São/Sã" for a healthy person body and mind, sanity probably has the same origin.

All this to say that probably she is also Croatian (or from Bosnia? since is a bit more common there) even though the name isn't commonly given today in both countries. All the research was just because I'm a curious person lmao only lost like 5 minutes of my time anyway.