Hi Jan-
Cabbage, Cabbage and more cabbage. Wrap it. Chilled may help a bit. Wear it
round the clock for as long as necessary.  Also elevate. Gently compress the
tissue which may press the interstitial fluid back into the lymph
circulation. Mom should be resting, of course.
Ask her MD about an anti-inflammatory medication.
If the tissue squirts milk, it will help relieve the pressure and won't
increase supply.

Linda Smith, private practice in Dayton OH