Mary was delayed getting to the lab as she and Bonnie were searching for Saori to help out with Ira's own encounter. By the time she got there it was too late to help out but it didn't seem like there was any major disaster at least. Seeing others taking the time to challenge their own Shadows as well she opted to stay around and observe how all of this worked.

She wasn't suspicious of Ales by any means, but she noticed him slipping away and she was able to guess at his intent. She followed along as stealthily as she could to avoid surprising him and as the process began she watched it unfold. She'd only intervene if it looked like he needed the help.