The division of labour in the Fillmore household is easy to caricature and worth stating accurately. Charles built the organisation, edited the magazines and worked out the metaphysical system. Myrtle ran the prayer ministry, wrote for the periodicals, edited the children's magazine, and answered an enormous personal correspondence from people who were sick, frightened or destitute.
Those letters are the most durable thing she left. They are practical rather than doctrinal, and they are notably free of the harshness the healing movements could fall into, in which a patient who fails to recover is held to have failed at faith. Her standing advice is to stop fighting the body, to speak to it kindly, and to expect improvement without setting terms for it, and she wrote to people at length, individually, for decades.
She was ordained in 1906 in the same ceremony as her husband, at a point when very few American religious bodies ordained women at all, and she held office in the movement in her own right rather than as a founder's wife. She died in 1931 at eighty five, having outlived by half a century the prognosis that started the whole enterprise.
Her practical bent shows in the arrangement she built rather than in any doctrine she wrote. Silent Unity was set up so that a request cost nothing, required no membership and was not answered with advice, and she defended that shape against pressure to charge for it. The ministry took the name because the workers held the request in silence rather than replying with argument, and it is the one part of Unity that has never been reorganised.