My stepdaughter is an unwed parent of an 11 month child. She is a recovering drug addict and a practicing alcoholic. She is currently on welfare and probation. She lives with her mother and me. She stays away from the house and her child most days and nights of the week. She leaves her child in our care even when it is necessary for us to be at work when she fails to show up at night or in the morning.

What is the criteria for having her declared as an unfit parent in the state of California and what is the process to gain legal custody of her child?

You asked for the definition of an unfit parent... and you provided your own answer. Addiction to drugs or alcohol, failure to provide proper care, incarceration,incompetence and repeatedly refused to give proper parental care.

Off the subject quickly, I hope you plan on taking full custody. From my understanding if both parents are unfit the child could be placed in foster care.

Have you given any thought of just asking her to sign over her parental rights?