A relative of two young boys killed in an apparently murder-suicide says their grandmother insisted on picking the children up alone despite the objections of their mother.

Connecticut state police say that after getting the children from a daycare center on Tuesday the grandmother, Debra Denison, apparently shot and killed them before turning the gun on herself.

Marcia White says the boys’ mother, Brenda Perry, had asked the grandmother to bring along another relative. White says Denison’s struggles with mental health were well known and Perry told Denison the boys were too much of a handful for her.

White is a paternal great-grandmother of the slain boys, 2-year-old Alton Perry and 6-month-old Ashton Perry. She said Wednesday that Denison wanted to pick the boys up because it was Alton’s birthday.