Johanna wasn't stupid according to her teachers she's far from it so nine years old or not she knows something isn't right. Earlier in the year she was at her great grandmother's house and found her crying over an old photo album when she tried to give her Nana a hug she gets yelled at, needless to say, that's why she's on her way to Uncle Stans this summer.
She quickly discovered she liked staying with 'Grunkle' Stan. Well, at least, when he's not getting her to work in the shop, Okay all he's doing is making her stock shelves but to a nine-year-old its torture. Also, as it turns out, he's the only one who gave her a straight answer when asked directly. A con man uncle Stan may be but he's honest when it counts even brutally so, it's how she learns she had another brother , a big brother granted he was only about thirty minutes or so older but still! She had a twin and nobody ever told her!
she disappears for a while after that but returns an hour later.
When she punches, Nathaniel Northwest in the nose, Wendy gives her a high five but says next time she can handle it. Stan had taken her to the park that day so she can hang out with some other kids and he could swindle some cash from some of the parents. So when Stan heard the girly scream he imeaditly looks up thinking she got hurt but when he sees the Northwest boy running away and Joey herself sporting a bruised and bloody knuckle, Stan grabbed his niece by the arm and leads her away.
At first, she thought she was in trouble, but when they got to the car, he starts laughing and tells her he's proud of her for 'putting the little punk in his place' and ends up taking her out for not cheap ice cream. In the end, Joey ends up getting punching lessons from her former boxer Uncle and she actually punches Nathaniel two more times over the summer. Stan wipes a fake tear from his eye and tells her he's neve been prouder of her. It's an unspoken agreement that they never tell her parents. Ever. '
Its when she goes home things begin to go bad for Joey. Dipper and Mabel start getting bullied at school, Dipper for his unusual birthmark and Mabel for her outgoing personality. In the end, she punches a lot more boys and girls over the course of the year and by the end of the school year, she's been suspended. Her parents are not amused by her excuse of "I did it for the Twins." the fight that got her suspended leaves her with a bloody lip and black eye but at the very least she knows that Dipper and Mabel are proud and that's all that matters.