What do you do about a woman that lies about your daughter ?

You're not saying everything here... as a mom, I see your concern and need to protect your family/child. But I don't know the extent or circumstances your daughter is truly facing. Besides, our kids will always lie/mislead/tell us what we want to hear... I know because I've done so to my own parents.... I'd evaluate the situation and question what is being said verses ruling the accusations out. Devils advocate, if you must. Now legally, your daughter can file an injunction to restrain the woman from coming near her, but as for speech, all that can be done is a small claims court defamation of character case. But you leave me questioning why your granddaughter was taken by CPS.... CPS doesn't just remove a child by word of mouth, they'd investigate and determine action based on the case workers notes and observations.

My sister's exes mom was crazy. She called child protective services on my sister. When they investigated our home they found it was suitable for raising a child. And this was when my sister lived in my mom's house with all our animals and all her siblings. I'm skeptical that they just took her away for no reason other than what the mom said.

If she is harassing your daughter, she should talk to the police.