Those 'healthy school provided lunches' do not look healthy... AT ALL! I avoided school lunches at all cost. Also, it's important to note that they don't always look after your health and offer a larger variety of options. I doubt they have gluten free, low carb, keto, etc. options as well. What happens if someone is allergic to something?
I find it funny that she didn't eat much in the end; I am guessing they rather have her not eat at all than eat something that her mother had provided for her. What her mother made for her is much better than some of the things I'm sure that school is serving.