There is NO WAY she is 15. The artists paints her as 11 at best. 12 if we're extremely charitable. Does that make Gray a pedo? Maybe, but I won't begrudge a guy for some light flirting, when the only action he gets is almost dying daily and the powers-that-be deemed her old enough to be in a trench war.
Unless it turns out that the world runs on 10-month years - then I will concede. But it never does now, does it? It never does...