Initially, when her first figure was revealed, the fact that she had similar eyes and structure to Chill made me believe she was an Undead version of Chill's species (I call 'em cyrosapiens in my fanfic guide), but her artwork has made it a bit harder to see the resemblence (I guess she could be a vampire-version?).
The updated/revised/newer art/design for Roller Brawl does differentiate her more from Chill, but I still believe they used the same basic wireframe and features which to me says "same species"