Examples of the singular “they” being used to describe someone features as early as 1386 in Geoffrey Chaucer’s The Canterbury Tales and also in famous literary works like Shakespeare’s Hamlet in 1599.
“They” and “them” were still being used by literary authors to describe people in the 17th Century too - including by Jane Austin in her 1813 novel Pride and Prejudice.
https://www.bbc.com/news/newsbeat-49754930
But really, what would Chaucer, Shakespeare and Jane Austen know about the English language?
Aren’t those cases referring to individuals you don’t know the gender of? Like “I saw a silhouette moving, they were going somewhere”
Sounds like the gender was known.
First one is plural, second one is refering to what I said in my previous comment
No, both are the use of the singular ‘they’ with gender. Read them more closely.
First one talks about mothers in general, second one refers to being a friend of someone
Yes, which is literally why many nonbinary people prefer “they” for their third person pronouns.
It’s still not used for the same grammatical reasons