please help :( expires tonite!!

This Sunday is the Pancreatic Cancer Walk and I started going last year with my great aunt and her family. But i just remembered I had it yesterday. So today my friend tells me she's having her birthday party on Saturday at 4pm-1pm the next day. So I ask my mom if I could just stay for only like a few hours and we could go back to the regular plan  sleepover my aunts house. But of course my mom says No! She says that i can either choose a. go to my sunts house for Fri,Sat,and do the walk on Sun. or b. don't go fri or sat. and i get to go to the sleepover but not even for the whole  thing! I have to leave like I would've in my plan and she would dive me the next morning. Its no fair at least to me I might be over exasturating. But i asm so mad/sad UGH! i JUST DONT KNOW WHAT TO DO ! And also my aunt would allow me too. She would agree in an instantAnd i want to go to this so badly because I haven't talked to her like really talked to her in awhile. And i love her friend Jacklyn shes just amazing haha. But of course my mom doesnt undertand that. And heres the worst thing I have to be decided tonite! Yes thats what i said tonite!!! Hopefully I can convince her but thats probably unlikely cause we arent really talking. I know mother/daughter problems. I know i should forgive her but i dont know. Maybe my sister can ask.

hugs,
Shannon