If your daughter's father is willing to sign somthing stating that he is willing to allow your mother custody then that might be an option. Also you can ask him to give up his parental rights to her. If he agrees to that, then you must know he will not be liable for child support any longer ( even if he does not do so already). Otherwise, your mother will have to file for custody in family court once you have passed and a judge will decide what is best for the child.