Wa `alaykum as-salamu wa rahmatullahi wa barakatuh.

 

It is your right in Islam to have your own place with your husband. Unfortunately many husbands might not have the financial means to provide that to wives and for that families live with each other. We ask wives in many cases to practice patience with husbands until Allah makes it easy on them to move out and be free financially.

 

Now on the other hand threating of harm and even killing is a serious matter! I am not sure of the seriousness of such claim but it should not be taken lightly if you truly feel that she might harm you or your child.

 

I suggest that you talk to both your husband and your father in law and have them deal with your mother in law to stop such claim completely.

 

Almighty Allah knows best.