Quoting Lovely Cocaine™:" it's my best friend's birthday and she's having a party tonight and i reallllly want to go but my mom ... [snip!] ... my friend is turning 19 and we've known each other since preschool, my mom knows this and doesn't even care. i wanna kill her!!"
Well when you have kids they are your responsibility. Your mother doesn't have to watch her, she is not obligated to. It's not her child. I personally wouldn't watch my grand kids so that my children could go party. They can find a sitter and pay for one on their own. It's a little dumb to be that upset about not being able to "party" because you have to stay home with your child.
You make sacrifices for children, if you wanted to party you shouldn't have gotten pregnant and had a baby.