Adult Cyber-bullying?

[Evy]

Since 2010 my daughter (she is 22 years old now) has been harassed, bullied and threatened on facebook by my ex husband's current wife (which he is currently separated from). I along with my 16 year old son has been harassed by her as well ..... As recent as this weekend. Police say they can't do anything about it because there is no proof that it is the current wife doing this. What she is doing is making up fake facebook pages (this weekend she made one of my exhusband.). She then request my son accept her as a friend, and because he thought this was his father, he accepted. Then she began a tirade of abuse.

My daughter went to the current wife home to ask her to stop. The wife called the police and my daughter was arrested. The wife lied and said my daughter had a 12 inch knife on her...which was a lie.

WHAT CAN BE DONE TO PROVE SHE IS BEHIND THIS?