our 9 yr old friends mom came over said she was showing her daughter porn on line what to do now?

[Sheri]

our 9 year old girl has been said to be showing her 11 year old friend some porn on the web her friends mom is the one that came over and said that her daughter had been acting weird lately and that she finally told her mom it was due to some of the stuff that our girl had been showing her when I (grandma that has been raising her since she was 10 months old) tried to talk to her she absolutely refused to talk to me and just shut down which is how she reacts to most everything that is upsetting to her she is extremely ADHD and has a hard time with concentrating on everyday normal conversations let alone ones that she either doesn't like or she feels she may be getting in trouble I do not know what I am suppose to do now I want her to understand that I am not mad at her and I just want her to know that the items seen on those sites are not what real sexual relationships are about