I belong to another site that is very much into critiquing so PLEASE don't be offended, I am just giving some general advice.
Looking at the photo sample you posted, I can see why they have a problem with exposure. The baby is under exposed and the background is overexposed. Flash in this case would have helped with the baby, it would have givent he babies eyes more depth and created "catch lights" as well as making the face look less flat. The skin tone can probably be fixed a bit with levels adjustment (as you can always adjust an underexposed picture - but you can't get data from an overexposed one). as for the background, there are some hotspots (pure white) and in all honesty if I am giving it a critiqu the orange thing that comes up in the background is very distracting to the image as a composition - you can most likely clone that out in PS with some of the leaves (which would get rid of most of the hotspots).
BTW cute baby:-) I also looked at your portfolio and you have some really nice shots of babies - particularly like the one with the bottle.
Canon 1DS, Canon 24-70mm, 15mm Fisheye, 65mm Macro, 100mm Macro, 70-30...