good luck, your going to have to deal with 2 different states laws.
mentle abuse is just as bad as phyical, if she is getting that bad then you need to prove that she is no longer fit to care for your daughter. your stepson is going to be a hole different story. maybe you could also prove she is unfit for him also, and get guardenship for him
as you know C.A has some laws out here but things are changing in the fathers behalf. the old about a father not being able to raise kid alone is going away faster every year....
good luck.....