One other thought occurred to me. If you're making a case for the photo having been taken in the 1920s (to suit the appearance of Esther as being more like a woman in her eighties than seventies) then the younger woman may not be a daughter in law. Weren't they aged circa 50 by then ? The younger woman looks right for a childless woman in her 30s, but not right for a 50 yr old who's had several pregnancies.

Or maybe she's a granddaughter ?

Jean C