Since you're on that realistic vibe, it would be nice to keep an eye on certain details, like highlights and values (the colors are distiguishable, but they appear to have a close 'light intensity'). Would also be nice to make the background a bit lighter to make the dark armor stand out more.
Speaking about armors, the design looks a bit pointy. It think it would feel a bit uncomfortable for a woman around the side of her breasts. I hope I'm not nitpicking, but remember when it comes to realism, the key for making something convincing is to think about the actual use of it (hope it didn't sound very complicated/weird).
You're on the right track, just try to pay more attention to details and your work will become much better. Good luck!