Kinship questions for MN?

Well I just recently got kinship for a relative and I seen a post that the grandmother is filing to get foster care for this relative will she be able to if he's under my care? I was told once he's in my care as Kinship no one can't touch him until the mother cooperates with CPS and courts. CPS told me by the looks the relative might not return to parent being she wasn't cooperating with CPS and refusing drug tests for them. I do have this mother added and all she talks about is getting high and what not. So is it possible for the grandmother to get this relative back if this relative is in with family already? Also this grandmother smokes Marijuana and does pills or you know snorts pills and has no job to care for this child and lives in a home that isn't suitable for this child? Sorry if I make this confusing.