[jml7c5]

In casual use, yes. In formal writing, the broad switch to acceptance of singular "they" is only about 15 years old. Up until that point it's the sort of thing that would be flagged by an editor, or lose you marks in an English paper.

[commodoreboxer]

I'd be shocked if that were universal over that time, given that even formal language has undergone many changes in attitude. Over hundreds of years, I bet that in many times and places it has not considered it a problem, particularly given its use in the King James Bible.