Help My Love Was Raped By Her Own Dad, What Do I Do?

I began noticing a funny attitude in my sweet heart, such as avoiding my advances and all, even trivial ones like peks,
She is a cutie, and I seriously love her. But I later got to find out from a very close source to her that
she was raped by her own FATHER. It set me back a bit. Especially with the problem of a belief in my part of Nigeria that
no one must ever marry anyone that has had any sexual relations with a blood relation, if it happens, the consequences are dire.
 Till today she does'nt know I'm aware of this secret of hers, what do I do?