Anyone! Please need advice!! Pretty shocking story!

This is ALL real! None of it is fake! But please be open minded to what I'm about to say and please don't not judge!!!

My friend told me that she did something really FUDGE up and she wants to kill herself! My friend Mother has cervical cancer. Well yesterday she said when her mom went to the hospital with her brother. So her and her father was home. Well let me cut this short, she said that her n her father had sex. Idk what to do or how to deal with this. I know its not her fault, she is the child n he was the adult, but her dad told her that he hadn't had any Cuz of her mother cancer! I need advice to tell her! I was in shock! Please help me to help her