OP...IF you were inclined to stop WU payment to this young woman, what exactly do you bring to the table?? You don't live here so you are super anxious and look at snapshots of her buying food. OK...what else? You are not here for her kids. You are not here to support her when times are tough for her. You are not here for emergencies or social events that you could enjoy together .
You are older than her and may have other directions in life.
So, I ask again...What do YOU bring to the table?? Maybe, just maybe, she is legit. If so step up or step out. You alone need to make this decision not advise from grumpy old men.