She's one of the method Mares that appeared in Made in Manehattan. She was unnamed, but someone on Reddit suggested the name , and it was chosen to be the placeholder name on the wiki.
Spoiler
And then of course her name becomes official in the S8 episode Horse Play. visitors can't see pics , please register or login
There is no way she isn't a reference to the Prince song. Just look at the cover for the 45 record of it: https://camo.derpicdn.net/7510d9e48dbf33d4947056224ca486ebf73edce7?url=https%3A%2F%2Fimg.discogs.com%2FSKINHlD3yBSqJkk49hN0upsNGRM%3D%2Ffit-in%2F600x600%2Ffilters%3Astrip_icc%28%29%3Aformat%28jpeg%29%3Amode_rgb%28%29%3Aquality%2890%29%2Fdiscogs-images%2FR-163030-1204073800.jpeg.jpg
And from last year is my Pear Butter one (I posted it to the FiM subforum, but not here).
The jokes are: One of Cadance's nicknames is "The Princess of Shipping". So I made a little truck trailer of it. As for the Starlight one: There's a portion of the brony side that hates Glimmy's guts (for some to the point where if she appears in an episode it's instantly "ruined"), so she's good at "mining salt". :sly:
I wasn't content with the HO scale model though, so I upsized Cadance's truck:
And I took an R/C car I've had since 1994 and made it into a ride for Tempest. The goal is to add straps so I can put my BaB Tempest plushie on it and run it around at a con (which sadly may not be until next year as there won't be a con in my area until then -_- ):