I was always 'fighting' against my ex-mother-in-law where my daughter was concerned. Her usage of words like 'Gee-Gee' for horse or 'goodies' instead of sweeets, 'doggy' and not dog and moo-cow instead of just cow etc., left her totally confused as I'd always taught her the right words.
My mother in law would day things like "She's only a baby Jakki, stop treating her like she's a mini you! she's just as much Brian as she is you. She's my grandchild and I'll talk to her how I like and how a baby understands."
It wasn't the way I spoke the words to her she was angry about it was the words themselves. In her world babies were talked to in baby language end of.
I was so pleased when one day Catherine aged 4 said to her granny "why don't you use the right word granny? It's 'DOG' not 'Doggy'! My teacher said so!" LOL... never mind I'd been teaching her that way all her young life, but teacher was 'God' at that time in her life

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What is it they say? Out of the mouths of babes........