My question is what can M do to get G in school w/o C.

Okay so I am a third party concerned citizen. but here is the story i have a friend, lets call her M. she is the grandmom of a 5yo called G. G should of started school 2 weeks ago. G's mother C, is an absent parent that just kinda dropped her off at her moms and went "somewhere they cant have children at." C has been saying that she was going to enroll G in kindergarten every day for the past three weeks. C has still not done it. My question is what can M do to get G in school wo C. C refuses to sign over the rights to G to her mother M. M is working Monday through Saturday every week to support herself, her adult mentally handicapped son and now her 5 year old grand child. She also ishaving to pay a babysitter (me) to watch Gso she CAN work. If the child was in school it would be less of a burden on poor M.M does not want to get DCF involved because she fears that they would take G away from her and C and be sent to some place that isn't better than her current situation. Her current situation is not bad by any means, M just wants G in school.