What are the legal implication of petition of custody?

ir I lost my husband in 2022, after his death I stayed with my in laws for 1.5 year but suddenly the behavior of the family changed my fil started asking for fulfilling his physical needs many dispute started there due my stay at there. In last july2023 my fil said when I am fulfilling all your need after your husband then it is your duty to fulfill my needs also, so after so much dispute over this I shifted to my mother home, now it’s been 1 year I am working in private company and my mother is taking care of my kids full day. Suddenly my mil filed as case under petition of sec-25 guardian and child act to get the custody. what will happen now?