What a dreadful situation for you but I really don't think anyone can give much help to you on so little information..... start at the beginning, why were you put in sole care of four grandkids and why wasn't their mum allowed to see them they seem the two most important questions to start it off with What ages are the kids what age and health are you? Where is their dad in all of this ? It all sounds very complex I don't think Social workers consider adoption if there are family members willing to take the children on together as obviously that is the best possible answer