Summer, as well as being the best (strategically speaking) female player. She is also arguably the best strategic player, full stop, although that is very, very debatable.
Even if she's not the best (I'd argue there is no absolute best) then she's definitely one of the best, and almost unarguably WG's best (and when you're WG's best that means you're one of the best :P)
The Best Female Warlighter this Year Award Goes To: 2/12/2016 22:24:36