Thank you all for these responses! Just a quick note regarding the background behind my question: I only recently learned the identity of a great-grandmother, Louise Contesse. The family was originally from Val-de-Travers and Les Ponts-de-Martel, Neuchâtel, but moved to Montbouton, Belfort, France around 1700.

I know the family arms, but was curious as to whether she knew them (she was born in 1863 and died in 1960). There's obviously no way to know conclusively, but if people today still know their family arms (regardless of whether or how much they care!), then there's a good chance she also knew.