There is a movement afoot (actually, the "movement" dates back many years, I suspect) to get rid of the awkward pairing of supposedly singular words such as someone, anyone, individual, person, ad infinitum with he/she or his/her and just go with they and their. Instead of
If anyone wants to leave, he or she should feel free to do so,
just say
If anyone wants to leave, they should feel free to do so.
Or, instead of
Somebody made a mess in the kitchen, and he or she knows who he or she is,
just say
Somebody made a mess in the kitchen, and they know who they are.
To be honest, I've had difficulty getting used the less awkward their paired with supposedly singular words, but I have been trying it lately, and no one on this site reprimanded me--at least thus far.
By the way, an interim technique of mine (and I suspect of some other weirdos) is to make the singular word really plural so that the pronoun replacing it has to be plural also. Instead of
Every individual needing a pencil raised his or her hand,
I might use
All those needing a pencil raised their hand.
Or, instead of
Every person here is responsible for his or her own property,
I might use
All people here are responsible for their own property.
Strict grammarians, at one time, may have been a little inflexible in this regard; loosey-goosey communicators nowadays, on the other hand, not so much. I say, "Go for it, user78655."
Oh, and anyone else so inclined, well, they too should go for it!