It seems like she may be billing based upon time. Time may be used as the key component for selecting an E/M level if the following conditions are met:
The provider documents total time and suggests tthat counseling or coordinating care dominated more than fifty-percent of the encounter.
Documentation may refer to: prognosis, differential diagnosis, risks, benefits of treatment, instructions, compliance, or risk reduction.
The documentation must indicate: the total time, the content of counseling and/or coordination of care, and that over half of the time was spent counseling and/or coordinating care.
One example is to write something to the effect of, "spent ____ mins of ____ mins counseling (or coordinating) care as documented above".
If all of these conditions are met, then time may be used to select an E/M level. 99215's time condition is 40 minutes, so if her documentation supports it then it should be ok.
Hope that helps.
Kris