Encountered: Chapter Nine - in the park, near the fountain.

As Aislinn and Seth are leaving the park, they encounter Scrimshaw Sisters; who may or may not be related to, or the same as, the bone-girls mentioned previously:

'"Thanks again for the save." Aislinn nodded then and walked off, heading straight towards the cadaverous Scrimshaw Sisters, who were gliding over the ground with their usual macabre beauty.
She'll swerve if she can see them.
She didn't. She kept walking forwards until one of the Scrimshaw Sisters drifted out of her path at the last possible second.' (pg103)