FC needs surgery, what are bio mom's rights?

I would ask the caseworker, since that is who will need to consent for the surgery anyway. Mom may likely have the right to refuse if the surgery is elective; since "elective" can cover a number of different situations, anything from cosmetic to "it will need to happen in the next couple years, but it's not urgent right now," what exactly the nature of the electiveness is may make a difference on that. Ultimately, it will be the caseworker who makes the decision on when/ if the surgery happens while the child is in care.

It is a situation where it will need to be done in the next few years. The caseworker is new and following the lead of her supervisor. Mom is supportive of the surgery, but all that can change.