Abusive, manipulative mother...

[Step-Mom]

I have been married to my husband for 1 year now...we are both over 40, barely. I have a 21 yr old and 14 yr old, the younger lives with us. My husband gets his 2 boys, 11 & 6 for 2 hours on Wed. nights and every other week-end. He has been trying to get her to agree to modifing the decree for 2 years now through written and verbal requests, to no avail. They have been divorced for 5 1/2 years. We had the boys for 30 days this past month, first time she has allowed it. During the first 2 weeks the boys connected with their father to the point of, the oldest telling of abuse issues from their mother. Phone calls were made to psych.'s to find out as the Possessary Conservator he doesn't have the legal right to request an eveluation. They suggested making a report with CPS. He did, they investigated. He obtained an attorney, who initiated a home case study done of us and interviewed the boys. We then obtained a TRO. At the hearing the case worker reccommended the boys stay with us until an independant evaluation could be done in both households. The CPS worker could not validate any RECENT abuse. I.E. No blood, scars, bruising, broken bones.
While they admit to evidence of past abuse, which the mother admited to by her testimony, they said they didn't see a problem with returning the boys to her since they implimented a safety net and that the boys now know how to call 911!!!
My question is: What kind of motions can my husband file to aid in this appalling situation. The eldest is suffering contiuously....WE NEED HELP. And time is not on the boys side. The attorney says"Give her enough rope and she'll hang herself" Is that worth jepordizing the boys? Not to us!