This makes a cute photograph, but I think that it would NOT make a good painting.
Watch out, that back foot does not even begin to "explain itself"...i.e., we know it is a foot, but it doesn't look much like one. Even if could draw as well as Peggy Baumgaertner, I wouldn't attempt it.
If this is a piece that you plan to use to get more work, grab your camera and get a better photo to work from...it will certainly pay off in the long run.
Your son is soooo cute!
Dress him up in something more "paintable". Plan a background, set up your lighting and go for it. Try to get a "closed mouth" shot to work with.