FAKE FRIEND

A college friend of mine transferred after her freshman year. I went to visit her at her new school about a month ago, and I found out that she is known around campus as the only AKA (since her new school, which is largely white, doesn't have a chapter). Now, here is my problem. She has told everyone that she crossed AKA at her previous school, the school we attended together, and I KNOW for a fact she did NOT. Should I allow her to keep on lying or just let it be known that she is not telling the truyth? Usually I wouldn't care, but she is telling girls that are interested in AKA, that she may start a chapter at the school, and is basically giving them false hopes in addition to false information. What would you do about this situation?