Lady Margaret Leveson Gower (d.1858) was the wife of Frederick Leveson Gower. They had married in 1851, and she died shortly after giving birth to a son. She was the daughter of Spencer Compton, 2nd Marquess of Northampton, one of whose family estates was Castle Ashby. The monument consists of a recumbent effigy wearing what looks like a nightgown, with hands folded across the chest, and head turned to face into the church, and behind, within the "gothic" embrasure, a marble relief showing an angel of very much the same proportions as the effigy, taking off into the sky, but looking down towards the body below.

A plaster model for the angel relief, at size of execution, is in a French private collection.