Visitation

I have a court giving me custody of my 7 year old grand daughter. It also gives the mother visitation rights. The mother is on drugs, she does not stay at home very often and she does not pick up my grand daughter for her visits. I am on Social Security and can not afford an attorney. I would like to get her visitation rights revoked complety. What can I do? Please help me. Thank you,

You may file a motion to modify custody based on her instability.