Who is the real Beverly Sutphin?

Beverly Sutphin is NOT a real person. Never was. She lives only in the demented imagination of director John Waters and in his ridiculously improbable mockumentary Serial Mom. Some people seem to have been misled by the foolishness at the beginning of the film about it being based on eyewitness testimony, court records, etc., but that was just a further expression of Waters' dark sense of humor and his attempt to draw viewers into his extended gag. Didn't it all seem rather outrageously outlandish, farfetched, impossible, esp. the courtroom scene?