This is a little old but I just stumbled across it today. From Buzzfeed:

12 Female Characters Who Keep Shaving Despite Constant Peril

When I finally get some proper time to get lost in its post-apocalyptic universe I will also offer some thoughts on the hairlessness of The Walking Dead‘s entire female cast and the stable/static facial hair of most of its male cast (with the exception of Rick Grimes) and the unchanging head hair of pretty much the entire cast (again, with the exception of Rick).

Why does only some hair grow when the apocalypse comes?