How is a mother-in-law addressed?

I never called my MiL anything. She never made any suggestions, and I was far too young and shy to ask how I should address her.

As I didn't see much of her, it wasn't usually a problem, but I do remember one occasion where it was difficult.
We were visiting her, but OH had gone out. Mil was upstairs when someone knocked on the back door. I went to call up the stairs to see if she wanted me to open the door, but I didn't know what to call her, so returned to the living room and pretended I had heard nothing! (I found out a long time afterwards that she had heard them knock anyway but didn't want to let them in !!!).

I thought it was just me, but now know that my much older sil (OH's elder brother's wife) never knew what to call her either. If the grandchildren were present, 'Grandma' was the obvious solution, but that didn't work if they weren't there!

My own lovely Dils have always called me by my first name. They also call my elderly mother by her first name, and she's perfectly happy with that. I find it hard to imagine anyone doing anything else in modern Britain, though obviously I realize that this is bound to vary between different cultures.

First name for me.

I called my MiL by her surname as in Mrs X.
My mum didn't allow us to call any older ladies by their first name. It was considered really rude. I couldn't break the habit. MiL was a widow and when she remarried I still called her Mrs X. Her other DiL just called her by her first name. I was very odd I think.
My DiL and SiL call me by my first name. Much simpler.

I never called my MIL by any name.My children's partners always call me by my first name.

Mother for my formidable MIL and Mum for my own mother.
Always felt right.

Didn’t call them anything. When the GC arrived, they became Grandma and Grandad, by me also.

My SIL and DIL call me by my first name. My sister, who is fussy about such things, is still either ‘Granny’ or her DIL addresses her as ‘Joe’s Mum’.

Bit daft I think.

I’m the same as Calendargirl I managed 50 yrs of avoiding the issue, but as we didn’t see the in-laws very often it wasn’t a problem.
Except for one day MIL asked me to go and ask ‘Dad’ if he wanted a cup of tea, as he was a sleep in the next room, I just stood there and called out ‘do you want a cup of tea’ loudly, she said that she could have shouted, but I just didn’t want to call him Dad.
All of my other in laws called them Mum and Dad, but I just couldn’t bring myself to as they were so horrible to me.

PS
my SILs always called us by our first names, as do our Nieces and Nephews

To her face Eileen
Behind her back the old bag!

I would never have addressed my parents in law by their first names so used Granny and Grandad once the children came along. I couldn’t have called them Mum or Dad as I had my own.
I’m addressed by Christian name by sons on law.
On the subject of aunties, it was common practice in my childhood to address familiar folk as Aunty or Uncle although always Mr/Mrs for older folk.
Ironically when our girls were little they called other friends Mums Aunty but some of my sisters in law didn’t want to be called Aunty so I had to say please let them call you Aunty cos you ARE actually their aunties!

My in-laws and my parents are referred to by their first names by their children’s partners.

My nan (in her 90s now) insists on being ‘mom’ or ‘nan’ to everyone in the family, including her children or grandchildren’s partners. My DH still doesn’t refer to her directly by name when we see her as he finds it odd calling her nan (which I completely get, she’s not his nan!), so he just avoids using her name. She’s very old fashioned in that way though, only people of her generation are allowed to call her by her first name, everyone else is either mom/nan/mrs x. One of my cousins cousins (so no blood relation to her) had always called her nan as a child, as a teen he once turned to her and used her first name, everyone went silent and her face was like thunder.

I never called my Mil anything as I was far too shy back in those days. My Dil's now all call me by my first name.

I called my MIL Mum and my Mum was called Mum by my DH (and the same for fathers). My DCs partners would always call me by my first name.
I had stepgrandparents who were known as Uncle and Aunty, much like my parents close friends. You could not have called that generation by their name but they were not grandparents so that was my parents' compromise.

My daughters in law all call me by my first name. Maybe when alone with my sons they may call me "your mother" or "your mum phoned she needs you to phone her".

PS said daughters in law are mostly in their 60s.

I never called my MIL by anything, nor my FIL come to that. My SIL called them Mum and Dad . I would have been OK calling them by their first names but that was never an option.

DW and I called our respective in-laws by their Christian names.

My sister called her MIL Mrs Broad for 40+ years, it was so odd hearing her?

I called my MIL mum, until I got divorced from her previous son, then I called her ‘bleeeeeep’!! ???

usually referred to as 'ESMERELDA' by my late husband

Mine has sadly passed many years ago but I used to call her by her name Margot, and sometimes I'd call her mum, no rule really we were very close so both were used

First name , when I got married back in the day some called their Mother in laws Mum but I hated that so used her first name , she wasn't my mother and certainly never treated me like a daughter.
My daughter in law calls me by my first name

Daughter in Law calls me mum on occasions . However her parents were not born in Aust and they use a traditional Chinese type parent name
Ditto with grandsons
So calling me mum isn't taking anything away from her mother
She refers to me as "your mum " to my son or nanny
I don't think I can remember her ever calling me by my first name. Many years ago when we were introduced I introduced husband and I by our first names.

I called my MIL “mum”. I was very fond of her and she treated me like a daughter. My DH called my mum that as well.

I never called mine anything at all.

Why would a grown woman call her m-i-l Auntie? I called my MiL by her name and my DSiL calls me by my name. I hope @kittylester is joking when she insists on being addressed as Mrs Lester!!!