MaryAnn is a sweet, mousy brunette Archon, previously in the service of Charlescomm, then croaked and decrypted during and after the Battle for Gobwin Knob, and now in the service of Gobwin Knob. She (along with Ginger) was selected by Parson to accompany him on his rounds.
Real World References
MaryAnn is a reference to the character by the same name on the television show Gilligan's Island. On the show, she was a sweet, naive country girl who was a contrast to Ginger's savvy movie star.