I don't Doris Wishman ever visited Plano, Texas but wow is this woman a dead ringer for her.  Right down to the shades.

Please look closely at all of the photos.  I don't use stock images; this is the exact item available for purchase.  Portrait was stored in a garage for decades and is fragile.  Regarding provenance:  This painting came from the estate of Emile Guidroz (1906-2006) and looks similar to other portraits he painted.  However, the signature indicated this was another artist - perhaps a student?