We started my LO on solid food at 2 months. I know it is not normally recommended, but the dr said based on her weight it doesn't hurt her nor will it give her any nutrients it was more just for the taste and to fill her up because she was a constant eater. She is also BF so she was getting the nutrient she needed. She was also doing all the "signs " of a baby who is ready to be fed. She would open her mouth when the spoon came near and get excited when she was about to be fed. I don't recommend this for everyone, but if you consult your doctor and you as a parent feel they are ready.. Then go for it ! My baby has been sleeping every night since about a month a a half for 10-12 hours a night . She was born at 8lbs 1 ounce 21 inches long and at 4 months has practically doubled her weight at 15 lbs 11 ounce and 26 1/4 inches long.
Wow, your pediatrician is pretty uninformed on more recent research regarding introducing solids. I would have found another pediatrician.
There are a million things wrong w/ this - your child could not possibly have been ready for solids unless at 2 months she was also sitting up unassisted and had lost her tongue thrust reflex, which I've never heard of until closer to 5-6 months.
Big babies, babies who nurse a lot, babies who look at spoons lovingly, etc. are not reasons to start solids. Sleep or STTN has nothing to do with solids.
The only source of nutrition until 4-6 months should be breast milk or formula. Then if all other milestones have been met, your baby might be ready. Introducing solids too early is damaging to the virgin gut. Their little bodies are not ready to process food, just breast milk.