Can my mother inlaw take my kids from me

Maybe. Without details we can't say one way or the other.

I can only tell you that it is usually very difficult to take a child from its biological parents, especially a mother. On the other hand, courts are charged with determining the best interests of the child. If they feel placing your children with their grandparents is in their best interests that may happen.

Details... we need more details in order to give you a proper answer.