Evolution as a process is factually proven. It exists, it happens, it's been experimentally verified, and absolutely no evidence suggests otherwise.
The theory relates to
how it occurs, and it's not "proven" because no experiment or discovery can possibly exist as stand-alone proof. It needs to be interpreted as evidence. The overall interpretation of this evidence is one of the most exhaustively confirmed and validated theories in any scientific area of research.
If there are any specific points that she uses as evidence against evolution, post it here, I'd be glad to help show her how ignorant she is.
Also consider this letter, supported and signed by 12,757 Christian clergymen:
"Religious truth is of a different order from scientific truth. Its purpose is not to convey scientific information but to transform hearts. We the undersigned, Christian clergy from many different traditions, believe that the timeless truths of the Bible and the discoveries of modern science may comfortably coexist.
We believe that the theory of evolution is a foundational scientific truth, one that has stood up to rigorous scrutiny and upon which much of human knowledge and achievement rests.
To reject this truth or to treat it as "one theory among others" is to deliberately embrace scientific ignorance and transmit such ignorance to our children. We believe that among God's good gifts are human minds capable of critical thought and that the failure to fully employ this gift is a rejection of the will of our Creator."
That's part of it, the rest can be found
here.