Legal Question in Family Law in California

There are no classes or tests that establish "unfitness". On the other hand there are some clear expectations of parents and if your daughter's mother is not meeting those standards you may have grounds to seek full legal and physical custody of the child. You should consult with a family law attorney to identify what your goals are and the reasons behind those goals in seeking to have custody of your daughter. A good place to start is age-appropriate parenting classes. A clue to whether there is a serious problem is your child's health and whether she is attending school and meeting age appropriate development goals and milestones. What will impress a mediator or judge (if things get that far) is how much your intentions are motivated by the needs of your child.