Gladys was a former member of the U.S. Army.
Background
Gladys was a retired United States Army soldier residing at the Sandy Coves Convalescent Home in 2077.
It is implied that despite her age, she was a dangerous woman, capable of escaping her retirement home at least thrice and having an assortment of weaponry, including grenades, within her room.
Appearances
Gladys is mentioned only in Fallout 4.