Can i keep my in laws away?

My husband and I happily married. But we are having a lot of problems with his parents. Mainly his mother. I am in the hospital for surgery and I chose for my grandma and mom to take care of our chikdren until I was able to leave. My husbands mother got so mad because I would not let her have our children. She said because I dont let her see them which by the way is a lie she will be taking us to court. We have very busy schedles so we go over to their house once a week sometimes more. I do not allow them to spend the night or for them to be alone with their grandparents. I don't have money for a lawyer but i would like stop their visitations. They would not be safe with their grandparents. My husband's father (grandpa) is a big time alcoholic and every week end all he does is get drunk really bad and he also smokes weed. i do not want that around my children. His mother (grandma) always tres to controll my husband and I when it comes to the kids and just about anything and Im tired of it. I NEED HELP!!!!