My question involves guardianship in the State of: California

I have a 5 year old step daughter that I have raised since she was 3. When my husband and I first started dating, he had full legal custody. So together we did everything for his little girl. I am a nurse and got her updated medically, since she was 3 and had not had shots since she was 1. We put her into preschool and she was growing up to be a smart little thang. Things were going great until the mother was granted 50/50 legal and physical custody.

a little background:

the mother lost custody when she was charged for domestic violence against Rick, (my husband now), back when they were together. They had been on and off for years and had a nasty marraige. She attacted him in their apartment complex. Police were called by the landlord who witnessed the incidence. A report was filled and a restraining order was put againist the mother. The mother was not allowed to see the father or the child and all legal rights were taken in guardainship.

Well, about 6 months ago they went back to court and because the mother had proof of some anger management classes, they allowed her to regain 50/50 custody of the child.

Rick and I were got married and I was wondering what my rights to my stepdaughter were, if any?

Just resently, I had to put a restraining order agaisnt his ex wife for myself because she is crazy. We drop the child off infront of our community police station, where the whole parking lot is on camera because of the craziness we know for her to do. Well, about 2 weeks ago while dropping the daughter off, she came after me and tried to attack me, screaming that I had hit her child and she was gonna beat the you know whats out of me...anyways, Rick stood infront of the car door and pushed her back. Within minutes, the police were out in front questioning her. They encouraged me to get a restraining order, so I did.

The mother is crazy. She blows up our phones, shows up at my work, shows up at our house. She had gotten drunk and called us to come get the daughter because she cant take care of her, then forgets the next morning where she is. Anyone who knows us, could tell you that she is unfit to be a mother....so how do we prove that in court?????