A friend of mine signed temporary custody of her son over to her sister while she was incarcerated.the sister was not taking proper care of child and came to visit and my friend the natural mother of the child would not let the baby leave with the sister.she brought the law up there but mother had left with baby can she have any charges brought up on the mother if so what kind the court was not involved in this case but it was signed by a notary public what does mother have to do to drop the temporary custody

Did the notarized paper say temporary custody or that it was any specific duration such as mom gets out of jail?

She should be able to stand by the now I am out of jail and want my son back. Thank you.
She can also press the issues of concern of how the sister was not taking proper care if the sister tries to turn it into a problem.

It will depend on what the court views, normally family court does not reconise any custody order that they did not issue.

I agree with Fr_Chuck
The notarized paper would basically only be good to prove that she did not kidnap the child
And possibly things like proof for if the child needed medical attention that she was authorized to okay it.
But not give her legal grounds to keep once the mom said she wanted him back.
The notarized paper means more that she is authorized to be caregiver and not full fledged legal right to not return.