Information about Vil’s mom has, as of this writing, only ever appeared in Vil’s Bloom/Broom Birthday vignette.
He explains to Jade that he never underwent any specialized magical training prior to NRC, to Jade’s surprise.
Jade insinuates that his natural skill was possibly inherited from his mother (as Vil’s father is not a mage), which is fascinating as Jade’s own parents are both magicless, but maybe magic typically considered to be hereditary as we have seen with Riddle, Azul, Epel, Kalim, and Idia?
Vil says that he doesn’t actually know if he inherited his magic from his mother. In fact, he doesn’t know anything about his mother at all:
I have no idea who she was, let alone whether she was a mage. Nor have I ever cared to find out.
Vil’s mother was not mentioned in Tapis Rouge (Vil’s equivalent of a hometown event, though he explains that he was actually born somewhere else, not yet revealed in-game), so that is all we know for now.
Twisted Wonderland Reference Note 