Revealing mistake: When Josh tries to be cool, when he leans against the wall with wet paint on it and gets paint all over his shirt it is clear that he is not actually leaning against the wall. This is especially noticeable the second time he does it.
Revealing mistake: In the scene where Jerry cuts the little girl's pigtail off, it is obvious she is wearing a wig.
Revealing mistake: When Josh is locking up the nuts in a silver tin, Drake asks for some nuts and Josh can't open it, It is quite clear at this point that Josh is holding the top of the tin so he can't open it.
Chosen answer: Well, she is the most liked sibling, so she can probably get more out of her parents, or get money from both of them without the other knowing, or as we saw in the Gary Grills episode she can get money from people easily by telling them all sorts of stuff.