I am A step parent of a 7yr old little boy. He knows me as mom even though she does get him everyother weekend. She signed her rights over 3 years ago and the judge gave them back to her when her grandmother wanted to see the child ( 1 1/2 later).
"How far"? Not sure what you're asking. Also unclear what you mean by the judge "giving rights back."
There are actually several elements of parenthood, and parents can lose one or more of them without losing actual legal parenthood.
It sounds like she's still the legal mother, and assuming that, if she sees him regularly for visitation and isn't in SERIOUS arrears on any child support obligations (like worse than 80% behind, for example), then there's probably NO likelihood of "stripping" her of those rights.
Hope that helps!