I agree with Kristy's suggestions about serving several choices. I'll reinforce the idea that she won't starve. All of us eat when we're hungry enough. When you provide a different meal for her when she doesn't eat the one you've served you are training her to only eat what she wants. It's not a battle it's a matter of training. Now that you've been doing that she will fuss and cry if you don't give her what she wants. Now you will have a "battle" of sorts. Tho I'd rather not think of it as a battle but that you're retraining. She will want you to change back and work at getting you to do so.
I have had some difficulties with my daughter when she was growing up and now my granddaughter because I take what I think is the easy way out but it rarely turns out to have been the easy way when I want to change it.
My concept of "picking your battles" means that what you do now is acceptable and you do not plan to make changes in the future. You are still students, you have a couple of weeks off. Do you want to spend the time on this battle? One that you have little chance of winning in this period of time.
I suggest you make small changes over a longer period of time. Don't "draw a line in the sand." Make meals a pleasant time together while you provide 2-3 choices that are already on her plate. Use Kristy's suggestions. If she does't eat any of them, tell her, "so sorry, this is all we have to eat tonight." If you have a snack later, give her a snack too. Again give her a couple of choices but don't work at finding just the food she wants. And make sure it's only a snack. She won't like being hungry and if eating isn't a battle she will eat.
When my granddaughter visits she is the only one for whom I'm cooking; I usually ask her what she wants for dinner. I give her choices. When she doesn't want any of those I shrug my shoulders and say that's all there is. She then chooses one of them. Our conversation is matter of fact. She still gets to make a choice but the choice is based on what I've chosen to provide. Sometimes she says she's not hungry and I then have dinner later at which time I cook what I choose. This has worked for several years. Shes 8 now.
Because your daughter is younger your routine will be simpler. The idea is to give her a choice without reluctantly "giving in" to her. You are still in charge.
Her mother doesn't give choices. She fixes dinner and then expects her kids, 8 and 5, to eat what's on the table. When she first started doing this they whined and begged and sometimes cried. Now they either eat it or not. My granddaughter cleans her plate and has seconds. Recently my grandson rarely eats more than a few bites. His mother can charm him into eating a few more bites but she's not concerned. He's at an appropriate height and weight and is healthy. Their pediatrician said that kids will eat when they're hungry and/or need the nutrition if one doesn't make a fuss about it. Her information made meal time much more pleasant at my dauhter's house.