Our sons girlfriend has called CAS twice to report supposed…

As I said, our granddaughters are with their mother (our daughter in law) almost full time for the last 4 years. Our son has them every other weekend. All was smooth sailing until this April when our son's girlfriend moved in with our son with her 4 children. Our son has taken them under his wing and treated them like they are his own and we also accepted them into our family like grandchildren like they expected us to however our youngest granddaughter was being rejected by the new girlfriend, in fact she wanted a paternity test to prove that in fact our youngest granddaughter was not our son's daughter. Well when that paternity test proved that in fact she is our granddaughter, both our son and his girlfriend still refused to pick her up for his weekends and the 4 year old was devastated. She had been very fond of her father, (Daddy's girl) We offered our help but it was refused. As I stated earlier, we stepped in when in June he again disappointed his 4 yr old daughter by not picking her up for her weekend with her father. He would only pick up the 6 yr old daughter and leave the 4 yr old with what they call an "unfit mother" yet our son would not allow us to contact our daughter in law. When we decided to step in and start seeing our granddaughters, of course that was arranged by us and our daughter in law, all hell broke lose. We are now not welcome at our son's girlfriend's new house where they are now living. They have cut off all contact with us but are calling CAS to report that our daughter in law is an alcoholic, compulsive liar and now are claiming that she is sexually abusing our granddaughters. CAS pulls them out of class during their first and second weeks of school to question them. They have searched our daughter in law's house for drugs and have found nothing. We observe two very normal young ladies whenever they come to stay with us which is almost every other weekend when their mother has custody of them. If fact we are picking them up in about an hour to take them horse back riding. Our son's girlfriend is just being spiteful with her calls to CAS which I assume that they must respond to even though there is no foundation for the calls. CAS does not give out any info. We suspect that our son may not even know that his daughters where pulled out of class for questioning BUT at this point we do believe that he is still brainwashed by the new girlfriend and we know that he really does like her 4 children. If fact he coached them in baseball this summer but never attended any of his own daughters games. He did tell in late that her would have gone to their games BUT his ex wife could not be there for that game. We went to see them play but only because our daughter in law gave us the schedule. Our son only gave us a schedule for the other 4 children's games and expected us to go to those games. We did not and so as a result,we are again in the dog house.

We want to know what we can do to protect our granddaughters from the emotional and psychological abuse that they are being exposed to.

I hope I have provided enough info this time.

We will be away until approx. 8 or 9 PM tonight.

Spending time with our Granddaughters.

Thanks

We are worried that these repeated calls to CAS are intended to have the girls taken away from their mother with the intention of just being spiteful to both her and us! We do not think that they really want full custody & therefore have 5 or 6 children full time, they just want to cause enough trouble to try to separate the girls from their mother and now us.
We are obviously concerned about the emotional well being of the girls and their mother. We feel that CAS will never find any reason to take the girls away from their mother but the frustrating part is that they seem to be able to just call and CAS has to go running with another investigation. Can this harrassment be stopped?