Philip remembers the lady in the photograph, but he knew her as Agnes May, known affectionately as Bopa Agnes.
He said she always seemed old, and was brought to various family parties with her equally elderly husband Charlie. .
He said that his mother's sister Sarah Ann (named after her Auntie Sarah Ann the sister of the boys in the photo) was called Sis by his mother and then Auntie Sis by her children, my partner's uncle (who I'm getting the info from, and his mother who has now died). Sis was apparently short for sister.
Hope that makes sense!