Cofelia

'''Matron Cofelia of the Five-Straighten Classabindi Nursery Fleet. Intergalactic Class. undercover on earth under the name Miss Foster''' was an alien "super nanny" in the early 21st century sent by the Adipose First Family to birth their young. She had her own sonic device, the Sonic pen. She was presumably killed when she fell from a great height after the Adipose ship's tractor beam suspending her was shut off on purpose to hide the evidence that Miss Foster had illegally used Earth to raise the Adipose young on. (DW: Partners in Crime)