I was a vegetarian for 10 years - the last 11/2 years was my daughters
first, so when we did introduce meat into our diet - she completely rejected it. Some staples in our/her diet is scrambled egg (with a little spinach and feta actually, but cheese in general is good and you can sneak in finely minced veggies), cottage cheese is one of the highest protein foods you can eat(more then meat)-mixed with berries (fresh or frozen/thawed)was an instant success. Beans are wonderful and can be prepared/mashed and mixed into just about anything. And Tofu can also be prepared many ways (even turned into ice cream! - Really!)A book called "How it all vegan!" has wonderful ways to prepare it, along with kid friendly recipes. You can offer soy milk instead of milk(or mix them)It's a little sweet, so must kids love it. My daughter has had many meals that were crackers, hummus, some cheese and a few of her favorite veggies like cukes and grape tomato's. She enjoyed making her own "sandwiches" and dipping in the hummus.
Then you can make things like pancakes with some wheat germ and/or ground flaxseed mixed in, or do the same with smoothies. (We add those or protein powder, my daughter gets to help - which she loves - and it's like drinking a milk shake, so enjoyed by all.
These are just quick thoughts off the top of my head. Try not to accommodate meals for her, but create a more versatile meal plan for your whole family. These are easy to prepare foods and just a few thoughts.
Another thought is that my daughter often decides she doesn't like something without trying it, or when I know she's had it in the past and enjoyed it. We are firm that she will not have a special meal made for her. If she tries something new and doesn't like it - we improvise and I'm mindful of kid friendly meals vs. grown-up taste/spice - often serving portions before adding the final spices and such. The first few times were rough - filled with tantrums, but after just a few times she understood that that was how it is and just in these past few months, I have a kid who used to be picky - who is now a pretty well-rounded eater.
Hope this helps.
good luck.