Fascinating! I didn’t know there was an article about this.

This use of singular they had emerged by the 14th century, about a century after the plural they.

That’s more than official enough for me!

Singular they has been criticised since the mid-18th century by prescriptive commentators who consider it an error.

1. Hey, it's prescriptivists again, ruining everyone's day
2. Look what's actually recent (if three centuries count as recent, but definitely more recent than seven centuries ago)

My child dresses itself.

"Ma, I'm a boy!"

I adore how callous that sentence sounds.