My daughter wants me to divorce my husband?

My 32 year old daughter has lied since she was able to talk. She once said my parents abused her when she was staying there( while I and her father was getting divorced ) she told the school this because she didn't want to stay there. It all came out that she lied my parents ed me once and they cried. Then she went to live with her father at age 12 and by age 13 she said him and his wife where abusing her because she wanted to live with me. This also was unfounded she says things to get her way no matter how awful and hurtful. Still at this age she does this, we have 2 grandchildren that we can't see because she is mad at us for who knows what this time. She sent a letter to my job saying I could never see them again unless I divorce my husband now she is accusing him of abusing her (touching her when she was little) My husband is devastated by this we love our grandchildren but she uses them as a weapon against us, do as I say or you won't see them and she punishes her kids with us (you didn't get good grades so you can't see your grandparents).She is a real work of art I don't know what to do if we push her she will cry ually abuse and my innocent husband could end up in jail because she is a liar. I just don't want my grandchildren to think we don't care anymore because we can't call them either (she has blocked our phones we can't call) The kids are 7 and 11, we raised the 11 year old for 6 years because she didn't want her. And the court system put her back with her because they are always better off with the parents right!!! Grandparents have no rights in Illinois even though we had all the proof in the world of drugs and drinking did us no good. So she says that is one of the reasons she hates me because I went to court with this proof against her. It scares me that she is such a good liar and gets away with it. What is to stop her from going to court if she gets mad again and press charges against my husband. How do you defend yourself against these charges? I hate that she has such a hold over us.