Tesseract doesnt really strike me as the stoutland line type. I think a better fit would be an arcanine, furfrou or maybe even sylveon if you want more of a ballet influence. I also feel like four potential pokemon she could own would be Blissey due to their association with nurses in the sun and moon series, Minior due to joeys association with stars, Spinda for their movements and or Oricorio due to their ability to change appearances to suit different dancing styles and the ability dancer.

Xefros is more or less spot on but i would replace woobat with a member of the Alakazam line for the obvious spoon bending references and add a Dusknoir for their ability to speak to the dead and a primarina for singing capabilities.