I think in the US Sasha is more accepted as a girls' name, even though traditionaly it's more of a masculine name,a short Russian nn for Alexander. So you're covered in that department.
That being said, also in the US it seems Sasha is a popular name for female cats. God only knows why this is, but it's true. A couple years ago we had a cat we called Sasha, a huge tiger-striped female. She was a mean machine, half wild.