Vent

So today is my daughter's first birthday and tomorrow is her birthday party. We'll my mom isn't coming to either. I planned her party on Sunday because it's when the restaurant was available and it's also my mom's only day off work most weeks. Well, when I told her, she got really quiet and didn't text me back for a few hours before telling me she can't go. Why? Because her fiances family is having everyone over for family pictures, and none of my moms kids were invited. She said it's an all day thing because his family is so big 🙄. Whatever, pick a man over your kids and now your granddaughter. Either way, plan b was for her to get out of work early and come over for a bit to see her on her actual birthday and just skip the party. Well she texted me half an hour before she was suppose to get out of work to tell me her job might make her stay late, then that she has to stay late so she wasn't going to be able to come out. Idk if I'm being extra sensitive to this situation because her and I didn't get along well when I was growing up and she always prioritized my siblings over me or if I'm right to be as angry and upset as I am. This is her first granddaughter, before finding out I was pregnant with her, my mom was pushing for my brother (golden child) to have a baby, but didn't seem as excited when I told her I was pregnant. She didn't some to any doc appointments even tho she was invited to every ultrasound, then threw a fit cause I wouldn't let her in the delivery room and wanted my MIL instead who had been to every ultrasound and every check up she could. Last thing she said to me was "ill make it up to you guys" but how do you make up for missing her first birthday?? How do you make up for prioritizing your bf instead of your daughter/granddaughter??? Would you be upset if your mom did this??