For the food issues, check out the book "Child of Mine." It is amazingly helpful. There are liquid vitamins that the doc gave us for my son, who was a preemie, but I would check w/ your pediatrician first. With the fruit, yogurt, and cereal, she is likely doing pretty decently nutritionally. Would she drink a yogurt smoothie? If so, maybe you can sneak in a few other items (carrot juice, pureed cauliflower). Also, there is some green colored juice drink (not green because of food coloring -- green from veggies and/or spirulina) at TJs, and I am amazed at how many kids happily drink it (not my son, mind you, but he does eat veggies). It tastes like apple juice. From what I have experienced, it's not unusual for kids to change what they are willing to eat at around 2. Whitefish spread was my son's favorite food (seriously!) until he was about 2.5. He hasn't really touched it since (he's now 5). He did the same thing with broccoli from age 2 to about age 3, when he started happily eating it again. However, given that your daughter is also wanting someone to sleep in her bed with her, all of the sudden, I wonder if the adoption of a new child, and one with behavioral issues at that, is affecting your daughter. As you working with the 8yo on his issues (and I think it is wonderful that you are doing this!), is it possible that your daughter is receiving less attention or feeling afraid of losing your attention? Maybe setting up some special times just for her (in addition to whatever else you are already doing) could help. With the food, just make sure she is staying on her own growth curve, read Child of Mine, and rest assured that many toddlers go through a picky eating phase. Btw, I second the rec for "Healthy Sleep Habits, Happy Baby."
Best to you and your family,
K.