My mom doesn’t act like a mom

Shes never been there for any of my pregnancies/giving birth since I’ve been living in a different state but now we live 15 mins away from each other. She knows I’m about to give birth soon to my last baby and she made a plan to go to Vegas for her friends graduation. It kinda does make me feel bad because you’d rather go celebrate your friend than your own daughter giving birth to your last grandkid? She was supposed to help me watch my kids while I gave birth since she’s my only family member here. I should’ve known from the beginning that she wasn’t going to help me.