Am I able to take a person to court for harassing myself and my daughter (under 16) on facebook?

I reported a local theatre group (that my daughter, 13, had been attending) for attempted crimes. The police investigated them for inciting sexual crimes against a female under 16.  The owners of the group started posting my daughters photo on Facebook and comments about her, while this was going on. They then contatced my work with an email of lies and many other connections with us. The police said it was harassment and went to see them and they apparently apologized and said they would do no more.  However they have continued, just not using our full names any more.  The police have said they have no juristication over FB and she has the right to free speach (what about our rights).  They suggested I ignore it, block them and don't respond so I have followed all their suggestions and they have continued with their FB comments.  The police this week contacted me to say they don't have enough evidence to take crime against my daughter to CPS, so that will be filed.  The owner of the group has now posted out with my full name, mocking the case and saying my daughter is a liar and photos.  My daughter is an emotional wreck they are destroying her childhood.  Surely they can't keep getting away with this.  I have now found out as people have contacted me with support as they can see the stuff being posted that this is not the first time this has happened and over 10 people that I didn't know have reported them for harassment and the police have been involved for various crimes.  What can we do to stop this and surely they shouldn't still be able to work with kids? The police seem very aware of them.

It has been suggested by another victim that we take a case against her altogether also is this possible?