So upset & hurt

My mom is great. I love her but it hurts me when it comes to my kids no one in my family comes around. My youngest sisters child had a birthday and my mom went with all the kids she has (oldest sisters kids, she picked drugs instead of them so my mom has temp custody) my sons birthday party is Saturday, my mom told me that she's not going cause she doesn't want to watch the kids at a park when she took them to one before. His last birthday I had to have it at her place otherwise she wouldn't of shown up. No one showed up for his baby shower. Every year its the same and it hurts because they are suppose to be family to us too