Engorgement?

[emmyg65]

Did she recently go through a growth spurt and/or start sleeping longer stretches?

[lilyelayne]

3 weeks is typically one of the biggest growth spurts so your supply is probably going up. For most women the end of this growth spurt lines up pretty well with the beginning of supply regulation, so hopefully the engorgement won't last too much longer.

If you feel the engorgment is causing a poor latch & hurting your nipples, maybe try reverse pressure softening?

kellymom.com/bf/concerns/mother/rev_pressure_soft_cotterman/