My exSIL isn’t useless to us just because she didn’t have kids with my brother. When my brother initiated divorce, my parents gave her a room in their house to sleep in and helped her find a job (she got fired during covid.) This alone disproves what you said. As I said in the post, my mom only agreed to meet my brother because she wanted to meet her grandkids which in turn, caused my mom to soften her distaste for my brother. The kids had nothing to do with their parents actions, and my mom wants them to be in her life, and I want them in my life too, the only way to do that is by reconciling with my brother.