Well, I've heard anyone currently working at Disney TV Animation can pitch a show, so it seems like working on Wander Over Yonder was what got her in the door in the first place. But she was just a storyboard revisionist then, not even a boarder, and her other jobs were similar (those last two things I'm pretty sure were just like independent films).
More than a lot of other people I think she just got lucky, like a right place/right time deal. She hadn't been in the industry long enough or in high enough positions to make it seem like she worked her ass off for it, I don't think it was nepotism either because of her previous jobs being so small by comparison to showrunner/executive producer. More than anything I think she just got extremely lucky, and that kind of pitch about magical shit was the kind of thing Disney was already looking for at the time-- what she pitched was close enough to that, and she was willing to go along with the suggestion, so it got made.
(there was how she went to Cal Arts, but that's more for how she got IN the industry in the first place, not how she got a show)