Very similar situation for me. My mom died of cancer when I was 24. She would have loved her grandchildren so much, and so often I wish I could share my amazing boys with her. My dad remarried a wonderful woman who is a great grandmother to my kids, but it still stings that she isn't my mom. To me, she seems more like a decent MIL - someone who loves my kids, is wonderful to have in the family, but certainly is no replacement for my mom and who can do little things that irrationally drive me a bit crazy

. I try to appreciate her for who she is, but still keep alive memories of my mom for my children (telling stories, sharing activities my mom did with me when I was a kid). My oldest is 5 and 'gets it' and asks me about her a lot, which makes me happy. It also helps that I'm close with siblings who struggle with many of the same things. Wishing you the best!