Anyway, I think the crock pot may be your answer for part of the problem. Meat and meat dishes in the crock pot is very, very easy. You can often prep the ingredients the night before and put them in the crock in the fridge, then stick the crock in the base and let it cook on low. You could cook a big thing once (like a bunch of boneless skinless chicken breasts) and then use for a while--like shred some of it for chicken soft tacos for him one night, cut some of it up and make a chicken salad for sandwiches, make a chicken cesar salad, etc. (Just examples here.) Soups and stews are also very good in the crockpot. I am not the queen of crock pot cookery, but I'm working on it!!
Sounds like for your DD you might need to just plan on a good snack for her for before you serve dinner and make arrangements to have that on hand. Like have some cut up veggies, cheese cubes, etc. ready to go. It sounds to me like the problem with the situation with her is only that you are sort of feeding her the snacks "on the fly" and they aren't really planned, so maybe you're kind of scrounging in the fridge looking for stuff to feed her while you're trying to make dinner. If you just plan on sitting her down with a plateful of snacks while you get dinner together it might make things easier. You may not be able to have her eat a whole dinner with you and your DH--maybe she can just have two mini-dinners, one when she gets home and the other when you all eat.
I have the same vegetarian/omnivore issues at my house--DH is a Hindu vegetarian (so no beef cooking here!) and I am an omnivore who is also eliminating most dairy due to BFing/DD's reaction to it. One thing that has improved my life markedly is that I have made a week's worth of menus and that's the basis for what we have every week. And I've made meals that can be "customized" with a little meat for me if I want but veggie for him. Here's a couple of our favorites:
1) Italian night--spaghetti with marinara sauce. You can brown a little ground beef or turkey and throw some of the sauce in there for your DH, keep the rest veggie. Salad--I buy the prewashed stuff, throw in some cherry tomatoes, done. Nice bread with olive oil.
2) Fajitas--cut up onions, green and/or red bell peppers, tomatoes. I saute these with some light vegetable oil and season with a mix of paprika, oregano, ground black pepper, salt, and cayenne pepper. (Or buy some fajita mix.) Separately I saute some chicken breast strips for me, and another pan I saute soy chick'n strips for DH. I sprinkle everything with some fresh lime juice and serve with tortillas. I buy salsa and/or guacamole, and serve this with tortilla chips.
3) Stir fry. I buy pre-cut veggies and cook them and serve over rice. I cook some chicken for me separately and add it in if I want to, and/or do some tofu or something for DH.
This is a couple of examples. I have found that it really helps me to know that Monday is always spaghetti night! If I am feeling exotic I can modify things a little and make penne instead of spaghetti, or pesto instead of marinara, but I have a framework anyway. This REALLY simplifies my shopping and cooking. As I go along I am adding some new dishes here and there from time to time. But I used to try to do meal planning by poring over cookbooks and coming up with exciting new recipes every night, and I just burned out, and I don't have the time or energy to do that anymore. I simplified.
The other thing is that I've realized that I just don't have time to cook everything from scratch, and that yes, it's more expensive to buy pre-cut fresh broccoli florets than a bunch of broccoli, and prewashed salad in a bag rather than a head of romaine, but it's cheaper than eating out all the time because I don't have time or energy to mess with chopping all the veggies myself with a baby that needs attention.
Hope this helps somewhat!