Separation agreement before going ahead for divorce.

We are not divorced yet and separated through an agreement, where in we decided that I move out of our joint property and she continue staying in the same house along with our daughter till she turns major. We also agreed on certain expenses and the EMI’s to be paid by me till we decide to sell the house. My question is , how can I prevent my mother in law to stay in that house whom I believe is the main culprit from the day one of our marriage, Can she file false cases against me in case I try to remove her mother from our house? What would be the best way to get a mutual divorce under Islamic law? Also, What is the credibility of separation agreement in law ? This agreement was made by her lawyer , obviously with almost all the points in her favour. Thanks