Another zombie; how delightful. As many have referenced, I got the “she is the cat’s mother” routine. As a kid I honestly didn’t realize I was being a rude git. BUT, now that I am “of a certain age” and have been around youngsters, I can see that it is a bit, well, if not rude, just, kind of low class.(Just so you know, I didn’t just recently stop using “she” in front of the person being referenced; I just started feeling the sting of it when I found myself around kids).
Grew up in Chicago in the 80s. Never heard the cat thing. I don’t remember there being any explicit rule about this, but it does feel a little weird to me to refer to mom or dad as “she” and “he” except where it would be awkward to keep repeating “mom” and “dad.” But I probably fall under the Polish cultural rules mentioned before. It’s definitely a respect sort of thing. But I’ve never been reprimanded or scolded for it. It just feels slightly off, like referring to my parents by name, which I have never done except in a tongue-in-cheek manner. (Well, with my father. I don’t think I’ve ever addressed my mother by her first name. It still feels odd to me to refer to my wife’s parents by their first names rather than Mr. & Mrs. Surname. All my childhood friends’ parents I still refer to by Mr. & Mrs. Surname.)
I think it’s about referring to a person who is present by a pronoun, as if they’re not in the room. Not necessarily reserved for parents or elders or whatever, just anyone, because you’re sort of talking about them as if they’re not even there.
I recall something similar with my Indian relatives—these conversations were all in Bengali.
When speaking of an elder the third person, you weren’t supposed to start off with a third person pronoun.
“Grandmother/Mother/Aunt stubbed her toe.”
Not: “She stubbed her toe,” even if it was clear whom you were talking about.
This was not restricted to women, but applied to all elders.
It applied even if the person wasn’t in the room, but it was doubly rude if the person was there.
That is the thing I am still confused about though. I can see someone getting mad if a child pointed at their mother and used the pronoun “She!” to start a controversial conversation or accusation. However, that would apply to anyone. My daughters would be going straight to their room with apologies from them afterwards after that if they ever did that because it is just plain rude.
However, the description given in the OP and by some others is really specific. It refers only to mothers and using the ‘she’ pronoun to refer to one in any context. That is something I have never heard before.
I am Southern by heritage and we also have very specific rules about addressing different family members and everyone else but this rule, as stated literally, is one that I had never encountered before this thread. I can’t even imagine how it would work without resorting to grammatical gymnastics and I still have no idea what feline family trees have to do with any of it.
“She…is the cat’s mother” was alive and kicking in Australia in the 1960’s.
I know other younger Aussies have posted, but just to reassure youse, it was around in my day as well. 
For those of you that understand this rule, please give some examples.
Here are some samples to judge:
On your wedding day, you give a toast. You say - “I want to thank my mother for being the greatest influence in my life. She made me the person that I am today.”
Your uncle asks you where your mother is. You reply - “She went to the supermarket and will be back in a little while.”
Are either of those offenses according to this supposed rule? If so, why? If not, what are you really referring to?
This reminded me of that bizarre episode in which Russell Brand appeared on MSNBC’s “Morning Joe” and managed to demonstrate to the three hosts that they were a bunch of clowns rather than serious journalists.
At one point, Brand scolds Mika Brzezinski for referring to him in the third person.
It’s at about the 5:05 mark in this clip — - YouTube
God I love that clip. Mika Brzezinski acting as if she is on the brink of orgasm just from being in Russell Brand’s presence. Katty Kay suddenly thinking that Russell Brand’s name is Willy Brandt. Brand so astonished at their inability to carry on with the show that he feels it necessary to demonstrate how news readers normally behave …
NM
Neither would have been an issue, IMHO. It’s about referring to someone exclusively by a pronoun when that person is present.
I googled for the meaning/origin the phrase “who is she, the cat’s mother?” and all the examples involved something like the following
Father: There isn’t any food
Son : She’s gone out to the store
Father: Who is she, the cat’s mother?
or
Son : She’s going on the trip with us
Father: Who is she, the cat’s mother?
Son: Sorry, Gran is going on the trip with us.
The cat’s mother part doesn’t seem to be important except as some sort of sarcasm. Pretty much any description involving a female could go after “Who is she”. Doesn’t have to be the cat or any of the cat’s relatives. It could just as well be “Who is she, the Queen of Sheba?” I can’t quite tell if it’s supposed to be entirely a politeness/respect thing (it’s disrespectful to refer to your mother/grandmother/aunt simply as “she” when her name/title hasn’t yet been used in the conversation ) or if it’s also meant to teach children that pronouns require antecedents ( Out of your two grandmothers, four aunts and six female cousins, which one is going on the trip?) But none of the examples were like yours where the mother was previously referred to by title, so my guess is that the rule wouldn’t apply to your examples.
I suspect that at least some of the people who go crazy over “she” being used to refer to one’s mother under almost any circumstances (like my father) remember being told not to use “she” to refer to various female relatives , but didn’t really have any idea why. People say and do things all the time without really knowing why.*
- My husband has a friend who used to constantly say “excuse me” and no one knew why. He hadn’t coughed or sneezed, and he wasn’t trying to break into a conversation. After 4 hours of a road trip with constant “excuse me’s” , my husband asked him why he was constantly excusing himself. Apparently he was “silently burping” and therefore excusing himself as his mother taught him to - but she probably didn’t realize that for this son she needed to explain that you’re excusing yourself for the noise, interruption, disturbance etc and if no one can even tell you burped, there’s no need to excuse yourself.
That’s what I assumed it meant. But if it doesn’t matter, why is that particular one used so much? It seems to cross all the weird boundaries where this custom is practiced, and be completely unheard of to anyone who doesn’t have the custom.
I am the latter. I’ve heard of “yes, ma’am” and “no, sir,” and I remember being told not to point at people to refer to them, which I guess probably would have also involved using a pronoun. But I’ve never heard of a problem with calling your mother “she.”
And, to be honest, I would think unkind thoughts about someone if I overheard a lecture on it. It sounds like the type of pointless strictness that I always let kids get by without when I babysat, so I’d be “cool,” which made it hundreds of times easier to get them to listen to me.
I always understood it was to with referring to someone in their presence. For good or ill, the polite thing is to mention their name at least to start off with, so it’s partly about making clear who’s being referenced, but also about not implicitly disparaging someone as just another anonymous “she”.
Why “the cat’s mother” stuck and other options didn’t, well, who knows? It’s a striking concept, perhaps (who, after all, knows or cares which was their cat’s mother?); and “the Queen of Sheba” is often used as a means of disparaging someone’s pretentions (much more likely in my family to hear, muttered sotto voce, “Oh Gawd, here comes the Queen of Sheba”), so it doesn’t quite work for the emotional purpose here.
I was called on this on at least one occasion in my childhood.
I think the key “offense” is being pissed off at mom and calling her “she”.
“She is a wonderful mom!” would almost certainly be OK.
Growing up in Pittsburgh (back when steel was king) I never heard the cat thing. Referring to mom as “she” was something I remember happening with step-moms. Divorce was a rarity (or so it seemed) and the kids with new moms hated them.
I’ve heard it too (I think a college friend mentioned it as something his grandmother said to him).
It was “the cat’s cousin” for me.
Don’t recall this OP originally. I have no recollection of this issue. Grew up in the Bay Area, CA.
From what I have seen with moms and their teens, the issue these days is to look up from their smartphones and participate in a reasonable, two-way conversation in person.
Maybe equating “she” with a *cat *specifically has to do with cats being, um, whores or something? Well, not whores exactly, but in the sense that one’s own mother should be accorded more respect than a common, litter bearing cat. Or something like that. I sort of “get” what is meant but I’m having a hard time articulating at the moment.