Power Struggles with Grandma

I get really upset watching how my mom handles Breanna's fits, which makes their relationship full of power battles. I'm sad to say that my mom was/is not a good role model as a mom when it comes to people relations. She may be an awesome helper for all the different committees that she's involved but in a family level, she's clueless. Now that she's a grandma things are a little different than when she raised me, but she's still not so great a role model. I'm trying to teach her not to lie to Breanna and to always be true to her word so that B can trust grandma. So far my little girl knows how to push grandma's buttons and initiate an rampage of grandma's emotions. Who know's? My job is to protect my daughter(s) and my highest goal is to help grandma be a better mother and grandmother.