This image of my 1.5 yrs. old son was shot with a Canon 550D / 18-55mm kit lens at 18mm. (f/3.5, 1/200, ISO-1600, handheld with window light only). I had to bump up ISO to 1600 even with the widest aperture available, which resulted in the high noise. No PP done apart from cropping.
For your comments on framing/composition, camera settings, etc. Will any PP improve the image further? Unfortunately, the image was shot in JPEG only.