First of all, if you number your pictures it is much easier to provide c&c
that being said, I agree with the above...
1. is cute, but would be better without the busy background (and of course without the extreme skin softening)
2. not a huge fan of the tilt mostly because I don't know what it is supposed to be conveying to me. Also, I don't really like having the tip of the other picture frame in the image. My other nit is the shadow right behind her, and the fact that her face looks a little hot/blown.
3. Not bad, but not really good either. For a shot like this the eyes have to be sharp. They might be in the original picture, but the smoothing kills whatever sharpness you had. Also, the shadow from the on camera flash is a bid distracting.
4. Not bad, a couple of thoughts though.
1. I would crop out her hand at the bottom of the image. Having just a little nub showing coming from nowhere tends to look a little odd.
2. I might play with having a different background. Perhaps a solid black sheet or something. It looks like your bedroom, which is ok, you can do these shoots in your bedroom, but typically you want to take the look that it's just in your bedroom out of the shots (meaning, if you set it up so that it looks planned then great, but if it looks like it was just there then that's not so good.)
3. again I would focus on the eyes. If those are sharp the whole image would improve.
4. for nude or implied shoots, one of the biggest things to work on is lighting. Each of these appear to be one on camera flash right at the person. I would experiment greatly with lighting. You never know what you will come up with, and I would say that would be the next thing to greatly improve these shots.
Overall, these really aren't that bad at all. The main thing I would suggest is merely that you back off on the softening.
YMMV