1. I like how you captured the expression and joy. A couple of things come to mind:
- Move back and zoom in (provided you have the space). The leg coming toward you is distorted and looks large. If you back up and use a longer focal length that "compresses" thee scene and objects will retain their proportion.
- For people shots, focus on their face, specifically their eye (maybe you were) but wasn't sure, because....
- It looks slightly blurry due to what appears to be camera shake. 1/25 a second is pretty slow (even at 21mm), well, for me it would be. Maybe a tripod. If you have a speedlight, or at some point get one bouncing the light and balancing with the ambient light will give you more options to use a higher shutter speed. Although, I can understand if you wanted to use the natural lighting.
- For my taste, I would do a more subtle vignette. Even a tiny amount adds greatly to the picture.
2. Good composition, the image may be slightly tilted.
-For BW conversions I like to add a little contrast, it seems to make the image richer. There are many things you can do for conversion to really make a BW sing. At a minimum I will usually increase the contrast.
-Similar to the first, it appears a little soft to me, probably due to camera shake. Although, your shutter speed was 1/60 on this one. Could still be shake, but it may also be the large aperture (f/3.5), probably one of those things or both contributed to the softness.
3. I like the composition and angle on this one too. Possibly over exposed just a hint.
I think these are good, just a few technical things I noticed, but I like them.