This seems unlikely based on the criteria that USFS has put forth. In the US Championships criteria, it just says "Athletes/teams who placed in the top 3 at the 2022 Toyota U.S. Figure Skating Championships" for group 3. Since there's never an asterisk that stipulates it must be out of senior-eligible competitors, I don't think that Bradie can be in group 3 so long as she's among the top 3 senior-eligible competitors, if she's not also in the top 3 overall.
Furthermore, since body of work will be the differentiating factor among skaters in the groups, Bradie really needs a strong showing at Nationals. She won't have a body of work while the other US ladies will, so she needs to blow them out of the water with her performance at US Nationals. It's really looking quite bleak for her, I'll be honest.