She definitely should not stress out over the resume. My son already had one from high school. (It was not his idea. I maintained it as a hobby to capture the cool stuff he pursued simply for the love of it. He never needed it for much in hs, but It was helpful reference when filling out college apps.) . It was a handy starting point for his initial college resumes.
It’s a common thing to have “imposter syndrome” at a top school. But if MIT accepted your daughter, I bet she will do just fine. Per gooble search, MIT still does the “pass / no record” grades the first semester… that will allow her to concentrate on learning and adjusting to college rigor w/o a GPA concern - http://web.mit.edu/registrar/reg/grades/freshmangrading.html