Richard Simmons' longtime housekeeper is petitioning to become co-trustee of his estate ... claiming Richard's brother pressured her to turn down the role while she was still grieving the fitness icon's death.
Teresa Reveles Muro -- who says she worked for Richard for nearly 40 years and was the one who found his body back in July -- filed a petition Wednesday ... claiming just days after Richard died, she, Richard's brother Leonard, and Leonard's wife Cathy went to view his body.