The one that hit hardest was the one I already knew but was said to my 4 year old in front of me.
I'd just had a miscarriage and was having a hell of a time with my ex, who had taken great lengths to convince DD that I wouldn't want or love her anymore if I had another baby.
Nobody know about the miscarriage, but DD had internalised the 'Mummy won't love you' stuff, so I had been on an 'of course not, Mummies don't stop loving their children, ever' reassurance thing.
I'd given up smoking (again) long before conceiving so wasn't over the moon about somebody smoking right beside us at the bus stop when we went to visit my mother. Again, not exactly fun, but knowing family is important...
Anyhow, my mother, a rabid ex smoker who thought it was easy to stop we don't mention the diet pills, tranquillisers and prescribed opiates addiction for the next 50 years must have caught a whiff of smoke on my coat and told me to get out and never come back.
DD was a bit upset and asked her why 'Because she's been smoking and I don't want her to come here anymore'.
'But you do still love her, don't you, Nanny?'.
The fucking bitch looked my 4 year old in the eyes and said 'No. I only love babies - it's why women have more than one, because you get sick of them whining when they get big, then you need another to replace them when they start school'.
What hurt wasn't what she was saying about me (I knew it already, it just hadn't ever been said in such bald terms before), but that she deliberately ripped my 4 year old's fragile security away from her with her words.
Seen her less than five times in the decades since (and all of those were instantly regretted because she always came out with something else as vicious as possible).