Hi there! Long time watcher, first time commenter. I was organizing my pics when I noticed something and remembered you wanted critiques - so, here goes.
The only thing that stood out to me as 'wrong' is fairly small - the light reflected in AJ's eyes doesn't look indicative of the light source in the room being in front of and below her. Instead, it looks like the brightest light in the room, when looking ONLY at her eyes, is above her.
Well, I've said something I DIDN'T like so I feel vaguely obligated to mention some things I REALLY like. The first is actually really mundane. I liked the messy line on the corner of the wall. It gives it that EXTRA shadowy feel, and for some reason it just seems right in this picture. As well, the shading on AJ and her immediate surroundings is brilliant, though, maybe it's just me, but her hat mayyybe need to cast more shadow above the right ridge. The colors used were spot on, and the expression on her face really makes you feel for her. Uhm. Sorry I couldn't be more technical? I hope you don't mind critique from a positively terrible artist!
Oh, awwww, just look at the adorable little Applejack; she's even more charming when colored! This is lovely dear, and I'm so glad you decided to do it... the warm uplighting is very dramatic here, and though in a way it pains me to think of it I almost have to wonder if Applejack isn't trapped by a fire or something here (hopefully not, but certainly it would explain such an expression/body language). Whatever the case may be though, I think it's great, and thank you so much for coloring it largely because I wished to see it!
Oh, well I am sorry for that! That was just the first thing that came to my mind... or well honestly, the lighting made me think of candles but I couldn't imagine Applejack would have any reason to be afraid of those.
Whatever the case may be though you're very welcome, and thank you again~! <3