"Sister's Mass"

Quite a dust-up over at Father Z's over a sister "starting Mass" without the priest.

In the actual quoted letter, the complainant doesn't say that the sister purported to have "started Mass" merely to have "started."
If the priest told her to "start Mass without him" he was certainly in the wrong; but perhaps he also did not phrase it that way, and knew that at most weekday Masses people are under serious time constraints, and figured that a Liturgy of the Word with distribution of Communion from the Tabernacle was better than nothing for those who had to get to work/drive children to school/break fast in order to take meds.... a million possibilities.
If indeed he would be there within a few minutes they should have waited, but since the complainant did not stay, we don't know if that is what happened.

It is important to be precise in our use of terms.
I've heard people say they went to "Mass at the Methodist church last week," or express preference for "Sister's Mass" in a parish that had to make do with Communion services, and I am almost always at pains to correct them.

But there are cases and there are cases.
I serve at a weekly service at a nursing home.
It is usually presided over by a deacon, maybe once every two months we will have a priest and there will be Mass Maybe once a month there is no ordained person available, and one of us lay people needs to conduct the.... is "para-liturgy" a correct term?

Anyway, people often thank the deacon for "Mass," I have been told several times that I "say the best Mass."
I do correct the other volunteers, gently I hope, especially the EMs who are, in some cases, extraordinarily ignorant. And sometimes I will explain even to an Alzheimer's wing resident that this isn't Mass.
But if a woman who sobs quietly for most of the day, and thinks I am her son half the time -- if for a half hour once a week she lights up like a Christmas tree with joy and remembrance, has all the words to the confiteor and wants to kneel to receive Communion from the first man she's seen in a cassock for probably 4 decades -- well, who am I to stop her from referring to him as "Father"?