Patrick once expressed his gratitude for Krall taking him because she was not coaching full time.
She was more of a technical specialist using the Dartfish software to help skaters with their jumping. Don Law had introduced Patrick to her and he started going to and staying with her so much that Law "fired" him.
Krall and Chan are a very good match personality wise as she keeps him loose and happy in both training and competitive situations. I am not sure if she is an all round coach as Patrick had a solid foundation from Mr. Colson and still lists Lori Nichol as his co-coach. At the time Patrick started going and eventually switching to Krall, jump training was and probably still is a priority so Krall fit the role well. Unlike Law, she does not "hoard" her student, instead she gets him whatever specialists and mentors he needs. She emphasizes Team Chan and discipline and system in his training. And that seems to be what works best for him now. I think Patrick's progression from a great basic coach to a cutting edge technical and scientific team contributes to his success as each way of learning is appropriate and optimal at each stage.
Krall is part of the team available to skaters training at Colorado Springs but I am not sure she has any full time student besides Chan. She must have seen how special he was and known how to bring out the best in him. She may still prefers to work limited hours and as a specialist and part of a team.