Re the mother nursing an almost 3 YO who developes sore nipples each
time she ovulates...... Soreness can last for up to 2 weeks and
clears by itself with no treatment sometimes overnight or
gradually...... soreness is extreme and it can become too painful to
nurse.  Also hurts even when not nursing.

I know of several non-lactating women who have developed acutely
sore nipples on the inside (no external sign) on exactly the same
monthly pattern you describe.  On the advice of a doctor specialising
in women's health, Evening Primrose Oil, 1 capsule per day, cured it
from the first cycle.  I posted about this some months ago.

Ros Escott
Tasmania Australia