Continuity mistake: When Drake is at the radio station getting ready to play his song, he is holding a 12-string guitar but when he races home to play for Wendy, he has the same guitar but it is now a 6-string.
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.