If im 17 and my fiance is 18 could my mom sign for us to get married even tho she doesnt have full custody?

ok im 17 and wantin to move out of my dads because im treated really bad here. my fiances grandma said i could come live with them but she would feel safer if we were married. could my mom sign for it even tho she doesnt have full custody? i cant take bein in this house and i really dont wanna get cps involved so if i were to get married would my dad be able to stop me from movin?