Should parents invite their mother when a baby is being born?

I bought my new grandbaby tons of clothes, all the baby furniture, give the parents rides everywhere, etc., yet, they told me that I'm not allowed to be at the hospital when the baby is born. It's mostly her that doesn't want me there, just my son. She uses me and she hates me otherwise. My grandbaby is being born today. I never got to see my first grandchild being they are all the way across the country. She is 6, and I've gotten to talk to her a couple times when she was very young. I offered to by my 6 yr old granddaughter a present. I told my daughter to keep the present at about $50. I have heard hide nor hair from them. I just feel like disowning my kids. It's heart breaking.