Hi J.---It's been a long time since my daughter had her adnoids removed but my son just had wisdom teeth removed and I think this might apply.
We us a great soy based protein powder for smoothies so we had alot of those. You can mix just about anything in a smoothie. To add extra nutrition, besides the obvious frozen fruit and yogurt, I added a couple of tablespoons of hot cereal (after it cooled) to the smoothies. You could also add frozen or fresh spinach leaves, ground flax or flax oil (ground is best for fiber and anti-cancer properties).
As for the red dye, you don't want your daughter to have that ANY day. Those dyes and other food additives are implicated in a number of health related issues.
I have a friend in Kzoo who can get you a can of Complete (smoothie protein powder) today. And please feel free to contact me for more information on healthy foods, food dyes, etc. I am studying wellness education through a Naturopath who has her PhD in nutrition. I have lots of files, recipes, articles that I can share with you.
Good luck! D. ###-###-#### ____@____.com