Trying to find this book?

[Paulena]

I am looking for a book about a girl that was found along a river and a village took her in for a while then they kicked her out and she left then on the road she met a woman that was rich and she had a school for orphaned girls and she took her in. She then trained her to become an assassin. I read it 11-12 years ago its an older teens book kinda romance but minus the sex.