What is this stone commemorating?

[arthurk]

According to A Vision of Britain, Countesthorpe wasn't a parish in its own right until 1866. Before that it was a chapelry in the parish of Blaby.

[Stanwix England]

Ah well, that rules that theory out.

[JenB]

A wheatsheaf was a fairly commonly used symbol on gravestones.
https://shadowsflyaway.blog/2017/08/21/symbol-of-the-month-the-wheatsheaf/

Added: apologies, I see this has already been mentioned.

[Ruskie]

Three feet tall and made of slate? Well, that is unlikley to fit with my “souvenir” theory.

Has your family member considered trying to contact the previous owner of the house in case they can help?

[pb_devon]

Has your family member considered trying to contact the previous owner of the house in case they can help?

Sadly deceased, plus it wasn’t a great sale/purchase experience as a result.

Great idea though!