Aunt refuses to vacate the house

Dear lawyers, my Aunt has been staying with us as a guest for free, for several years now. She is my father's sister. The house is legally on my mother's name. We gave her a room in our house and allowed her to use our kitchen. Apart from this, she has also been using our electricity for free. After my marriage, we found that we were falling short of space and asked her to vacate her room. She now refuses to vacate saying that this is her house now as she has been staying for so long and there is no law that can make her leave the house.