Sorry I forgot who posted this, so I can't address you by name, pardon...
    Based on the location of the plugs it certainly could be a bra issue, as
Sarah mentioned.  As for her job as a PT, does she do cardiopulmonary (chest)
PT? If so that may involve the old "cupping and clapping" on the patient
-some moms, especially with erratic toddler nursing as well, are  susceptible
to plugs related to vigorous, repetitive upper extremity motion. If she works
with orthopedic patients demonstrating use of crutches, that might also
compromise local drainage. Sometimes what one mom's breasts can tolerate,
another's cannot. Good luck!
                                                      Judy Fram, Brooklyn, NY