if you like the image, id say you did well PS'ing the arms out. . .

Good work. . .

I question the lens focal length and distortion, (there is nothing wrong with distortion if you use it properly in the shot), but in this case I think you tried to get a wider shot and instead of moving back with a longer lens, you moved in with a wider one and distorted the mothers face.

I dont think it's bad to use wide lenses, I like them a lot but if you want more "true" you need to shoot above 50mm. for a shot like this, I would have been at 50 or better so as to NOT distort either subject.