Here’s the short answer: Your primary objective is to limit your daughter’s exposure to both her father and his family as much as you can. No Contact would be best.
To look at this further, I’ll describe three scenarios involving a sociopath’s family.
- The family is also sociopathic
Sociopathy is highly genetic. Therefore, if your ex is a sociopath, it means that one of his parents is disordered, or there is disorder somewhere on the family tree.
If the parents are disordered, they, like your ex, are incapable of love. They are incapable of being genuinely concerned about your daughter’s wellbeing.
So why would they want to see their granddaughter? Because, just like the sociopath, they view her as a possession. They want what they perceive belongs to them.
Therefore, they view access to your daughter as a battle that they want to win. If they have money, they may keep fighting until they win.
If your daughter were alone with them, it’s possible that the visits would be okay. Or, she might be neglected, abused or even kidnapped. And yes, I do know of sociopathic grandmothers who have kidnapped their grandchildren.