The and such...
1. People are long and narrow; portrait orientation is long and narrow. You've used landscape... as a result you've clipped bits of the child's arms. Cropping limbs is okay if you need to, but always do it boldly, never at/near/through a joint and never along a lateral axis. NEVER crop off little bits as in the cuff of the left arm. You've made good use of what looks like great window light, but the left side of the image is rather dark; a reflector would have solved this. A large piece of white card-stock, a sheet... anything like that held off-camera image left would have brought in fill light and evened out the exposure. Avoid black clothing when possible as it's more difficult to light well.
2. Better lighting here in that it's less harsh than #1, but it's 2/3 - 1 stop under-exposed. This could be tweaked easily in post. Again, watch the crop (disembodied hand lower right).
3. Something with the WB here; he appears slightly green on my monitor. The whole image seems slightly soft, likely due to motion blur as a result of the slow (1/40) SS. Remember to keep your shutter at speed at 1/FL as a minimum, and unless you have unusually steady hands, avoid going below 1/60 until you are more experienced.
4. Pretty much the same as #1, but a better orientation within the frame.
Just my $00.02 worth - your mileage may vary.
~John