My 8 year old sister was abandoned by her mother at the age of 4 and my step father is taking care of her. Would my mother be able to take custody of her? Even though she is on drugs and unfit?

I would be asking that question to a local attorney as I was finding out how much his retainer would be.

I cannot answer that question with any certainty, but what I am certain of is that when you go to a court and have the proper documents prepared , it will eliminate ant chance of that happening.

Some crazy things happen in spite of law and the best of intentions. A drug addicted mother who abandoned her child , then gets the child back would not be the craziest thing that has happened I would wager.

I would urge you to consult and attorney and find out what you need to do to prevent it.

I wish you well.

A step parent has no legal rights, and normally can not legally put child in school or get medical treatment.

And yes a parent who was abusive, if they can prove they have changed, are often allowed or given another chance.

There needs to be things done though court