Mariah had the 3rd highest score, which she got at Broadmoor. Before her were Vivian Le and Tessa Hong. Vivian was doing JGP and Tessa was age-ineligible. Tim Dolensky had the highest score, which he got at Skate Detroit, and he got the SkAm TBD.
I think Angela got the spot first and then w/d for injury and Mariah got it. I think USFS weighs nationals placements heavily as well.