Hi Lisa
Write a note to the tree owner and send it to my genealogy email address ( faircork-tree (at) yahoo dot co dot uk ). I'll paste it into an Ancestry message to the tree owner. Then cross your fingers and hope that she'll read her messages and respond.
Even if nothing useful comes of this, at least you'll be able to offer to pass on to her a copy of that photo of Minnie you mentioned. Maybe she's never seen a photo of her great grandmother and will be delighted ?
Jean