Most of your recent drawings (not including the above) seem like the eyes are too far apart. I like what you did with the eyes on your recent one though, and I feel to draw shy/awkward looking faces you just need to have them looking away and have their head tilted downward; you know? The male drawing you did above though, it feels like his left eye is WAY to close to his ear and if he were to look straight at you there'd be 4 inches of space between each eye. I feel like noses help artists dictate where to put the eyes, but due to anime's "noseless" style that can be hard but just kind of imagine where the bridge would be and have them no more than an "inch" away from the nose area. In some of your pictures it feels like their almost an inch and a half or two inches away from the bridge; while I'm not actually measuring them you get what I mean I hope.
You've basically nailed it on your last one but as far the eyes go if you want them to look more shy and "guilty" you have to have their eyes lower and more solemn looking. The blush works well too, and you have to make sure their eyebrows don't make them look too intrigued as that's the opposite of shy. Your current work looks more like she's wondering what she's looking at, and I believe that's what you're going for but just commenting on the previous discussion.
Here's a pic I found that pretty well depicts a "shy" anime girl