What are my legal rights to my one year old granddaughter? My son was 15 and the mother was 20. She was given temp gard so he could complete school.

My one year old granddaughter was conceived when my son was 15 and mother 20, whom was the daughter of a very close friends of the family. The two were raised as “cousins”. I signed temporary guardianship papers in order for my son to finish out his school year, instead of transferring to a new school. 3 months later ends up saying she’s pregnant. I found out days before the child was born that this is in fact my grandchild. Finding out recently that her mother warned her not to buy drugs and party with a minor. My son is not aloud to be on the birth certificate so she doesn’t get in trouble. My granddaughter is used as a pawn by her mother saying when she can come and not. I hand off, with the mother everyday so my granddaughter will know her fathers family equally. Now, the mother is saying someone from “our” home has treated her inappropriately. I struggle every time she leaves with her mother, beings she IS the perpetrator.