... you refer to a practice that has grown up among the sisters of washing and anointing sisters who are approaching their confinement [before childbirth]. If so, this is not, strictly speaking, an ordinance, unless it be done under the direction of the priesthood and in connection with the ordinance of laying on of hands for the restoration of the sick.
There is no impropriety in sisters washing and anointing their sisters in this way, under the circumstances you describe; but it should be understood that they do this, not as members of the priesthood, but as members of the Church, exercising faith for, and asking the blessings of the Lord upon, their sisters; just as they, and every member of the Church, might do in behalf of the members of their families.
[Source: 4.19 Wilford Woodruff, Letter to Emmeline B. Wells, April 27, 1888, as quoted in Matthew J. Grow, Jill Derr, Carol Madsen, and Kate Holbrook, editors, The First Fifty Years of Relief Society: Key Documents in Latter-day Saint Womenâ™s History, The Church Historian's Press, 2016, https://churchhistorianspress.org/the-first-fifty-years-of-relief-society/]