Who is The Rhea Sisters from Invisible Monsters and what is their importance?

The Rhea Sisters are three transvestites who have made a fortune both from selling a talking doll and from their entertainment act. The Rhea Sisters took in Shane McFarland not long after he was kicked out of his parents' home and were behind the horrible hoax perpetrated on the McFarland family when they were told their son had died of AIDS. The Rhea Sisters convinced Shane to have sexual reassignment surgery and have paid for all his surgeries up to this point. The Rhea Sisters consider Shane family and intend to continue paying for his medical bills for as long as he wants them to. After Shane is shot, he is taken to the hospital because the bullet managed to miss the bullet proof vest. The Rhea Sisters come to the hospital and repair his makeup, bringing back Brandy after Shane has surgery.