New this and need help

My Name is Margs, and while I have known about PAS it has been impossible to prove. Just last week my x husband's live in girlfriend of 2 years has left him and come to me re: the admittance of providing false affidavits and lying to the court expert. I am pleased she has come forward but not sure what to do next. She has just been to see my solicitor and just now it has hit me like a train. 

I am after any advise of what I can do to be able to see my kids calm and happy again. 

thanks