Yup, what you said. Sketchy is by any means is one of the best support fighters in this game, to use in Prize Fights and Rifts to counter certain modifiers. Most players have more than 3 Gold Sketchy on their Collection for Rift only. She has value.
Sketchy has a surprisingly decent ATK stat for a Bronze character, allowing her to deal decent damage against opponents from a higher tier. Sketchy is often used as a support fighter for offense, hence investment in ATK, Piercing and Meter Gain may be useful to increase her damage output and act as an emergency fighter, although keeping her in reserve is still best as she needs to stay alive for her abilities. If nothing else, investment in HP, Defense, and Block Proficiency would keep her alive long enough to TAG IN to another fighter.