J.J.
Hi, I also have two children who are very much on the light sleep since birth.
My youngest one is 4.He is usually up at 5:30 or 6 am, furthermore he was always dreaming a lot and cranky in his sleep, he was also very hyper thru the day and moody. He used to wake up a lot at night.
I decided to go to a natural doctor and I learned that his eczema was related to an stomach fungus and also to a sensitivity to wheat, dairy and white refined sugar. All those things made him extra hyper and moody. Since then I have changed his diet, and the reduction in wheat and dairy (he takes soy milk without problems) has made a huge difference in his personality, sleep and eczema.
Now he can have some of all those things with some enzymes that help him digest it better- and I can adjusted his diet based on his behavior and rash- We also have included a lot of "sporty activities" like swimming, walks, bike rides, hikes and that made him tired and relaxed and that helps him to sleep sooner at night and also thru the night.
I knew he was not a moody kid or super hyper. I had the feeling that he was just not himself. I went to his pediatrician and their answers did not help me. I tried the alternative approach and that just help him became the happy boy he is now.
Hope I was of some help
Good luck