Well, I bet she won't say no to popsicles :)
Get a set of Tovolo popsicle molds (they're BPA-free) from, say, Amazon.com. Then, stick stuff in your blender. It will taste good, won't set off any meal-time fight alarms, and will be very nutritious if you do it right.
Here's a recipe: 2 cups cooked, drained, and cooled white cannellini beans (or I guess cans of them, rinsed thoroughly and drained)
1 cup almond, soy or rice milk (vanilla)
1 teaspoon cinnamon
1 large ripe banana
3 tablespoons maple syrup (or agave nectar)
1 1/2 teaspoons real vanilla extract.
(You can hide beans and vegetables in lots of things like this. Spinach and Swiss chard are great because they're very mild. Carrots, too.)
Blend, pour, freeze, enjoy :) This way, she gets her protein from the beans and milk, some fruit, and cinnamon is good for her, too.
Get a juicing recipe book, and simply freeze what you juice instead of drinking (or of course give the juices to her to drink). There's a great one by Victoria Boutenko; I think it's called Green for Life. She has a lot of juice recipes.
Also, make *snacks* healthy. Her nutrition doesn't have to come from mealtimes alone. If you can give her nutrient-dense snacks, you can do a switcheroo. Essentially, she will think of her snacks (cereal) as meals, and she "wins" by getting what she wants for "meals," and her mealtime nutrition will be snuck in through snacks. Instead of cookies and crackers and candy-like jelly "fruit" snacks, give her hummus, apples, yogurt, etc. Make things fun by making them look like faces. Do "ants on a log" (carrot sticks or celery sticks with peanut butter and raisins). Things like that. Just be casual about it and make sure she doesn't see how much you want her to eat that good, healthy stuff.
For snacks, consider leaving out a nibble tray (ice cube tray) of all kinds of healthy treats. That way, she can choose. Studies show that toddlers choose what their bodies need. So let her pick from a great variety. Include things like quinoa, millet, amaranth, or some other nutrient-dense grain, flavored creatively with something not too salty (try watered-down sweet potatoes! Thick soup! Etc.). Have lots of veggies. Have some kind of dip, like a healthy salad dressing or avocado or guacamole.
Never be a short-order cook. If she rejects what you put in front of her, don't go find something "yummier." This sets you up for failure. She'll learn to reject pretty much everything.
Maybe let her catch you enjoying healthy foods. When she demands a taste, be like, ok, here, and if she likes it, gloat secretly to yourself. If she doesn't like it, no big deal.
You can find some really great recipes in Super Baby Food by Ruth Yaron. Your kid will be vacuuming up good, healthy foods before you know it.