It sounds like the second girl who majored in Biomedical Engineering deserved to get in. I hope she does something with degree other than working for Big Pharma.
My son is currently in his last year at UNH studying Biomedical Engineering/Science. He could not get into Dartmouth or Harvard. He could have gotten into WPI but decided that the difference in the debt was not worth it. It would have still cost $45K/year after grants to send him to WPI(Worchester Polytech Institute). He wants to go to Dartmouth for grad school.
If he has a high undergrad GPA ( > 3.8) and decent GRE and faculty recommendations, he’ll get in anywhere he wants.
Don’t sweat it. The rules for entering grad school in STEM are far different from undergrad.