NotDonna
Most cereal bars are marketed as being low cal so its a case of just looking through them at the shop and avoiding any under 100 cals (that's most the them sadly). The Quaker to go golden syrup bars are quite little for around 200 cals each. 2 of those would be good. My dd likes the Belvita milk breakfast bars which again are around 200 cals. They're fairly plain with no nuts. There are some Nature Valley plain ones that are very like flap jacks.
You can stir olive oil into cooked pasta and rice. Start off with a little and build up. A spray bottle with olive oil in is handy and you can spray some on naan bread etc and it soaks in.
Add double cream to her hot choc. Again start off with a little bit.
Add a splash of double cream to her yogurt.
You can stir unsalted butter into pasta sauces, curry sauces etc and it blends in well. I separate some off for dd as I definitely don't need the butter. Add ground almonds to curries.
If she likes cheese with pasta and sauce, bolognese etc put some on the pasta before you put the sauce on, then more cheese on top.
If she has cereal for breakfast you can mix double cream with her milk.
Very slowly increase portion amounts.
She might not be strictly in ED territory but if she shows any signs of wanting to control what she eats, seems to be preoccupied with her looks, starts to refuse previously liked foods because they may be 'bad' such a pizza or increasing exercise then that could be a sign she's struggling with thoughts in her head, so that's just something to look out for.
I can't help with the brace issue. I hope it's not too uncomfortable for her x