Ok but you are going to have to list many of the "things" you have tried. If she is mounting each of you against each other, then you need to show a united front. This means you all have to agree on at least some aspects of the effort, and if possible, confront her with that effort all at the same time (in one way or another, if not physically be in her presences then open letters stating the same acknowledgement.)

WHAT types of lies is she telling? Can you figure out her main reasoning?