My first was a great eater. He's 4 and wants steak, broccoli, etc... First, relax. No kid has ever died from being picky. The more you tense up, the more your child does. It may be a power thing not a food thing.
That said, my second is picky. She loves something for weeks, then hates it. Wont do much meat and veggies. Loves carbs and sugar (argh!). She is 2.5 yrs..
To get more into her for calories (10% percentile weight), I use VRUIT. Its a veggie juice that has NO sugar added. I mix it with water for her other than whole milk drink. She gets calories and vitamins. I make sure to clean teeth/gums though due to the sugar occuring naturaly in it.
I also make lots of smoothies. VRUIT juice, frozen berries from costco (big bags) and a fresh banana. Sometimes if she needs the calories I add a natural, organic no sugar added yogurt (stonyfield). She loves these and thinks its a treat and I get all sorts of veggies in her this way. Whatever smoothie is left (I may have some too! good for colds!), I pour into popscicle molds and freeze for treats. She and my son love the popscicles as do the neighbors and it is healthy. No added sugar, lots of veggies. They have NO idea. Works good.
Just keep leaving out the veggies and she will eat eventually, let her be hungry... she will eat. Also be sure to let her SEE YOU eat them... maybe have afternoon snack always be fresh veggies. Make a big production out of it and you sit down and dip your veggies with her (a tea party) and she may try. If its the only snack available, she will eventually try as she will be hungry. Obviously you are not starving your child but there is nothing wrong with them learning what hunger is... oh, also, BIG veggies sliced thin can be then cut into nice shapes with cookie cutters, let her pick. She may like that too.... good luck.. relax... she may hate veggies until she is 18 or 28... ahahaha