Debi,

Can I assume this mum has tried Kegel (pelvic floor) exercises to
help "tighten everything up"?  If not, I would certainly try that
before giving up breastfeeding.

If she's never done Kegels before, have her practice by stopping the
flow of urine a few times until she gets a feeling for it.  If the
prolapsed uterus makes tightening the pelvic floor uncomfortable,
suggest she get into a "bridge" position:  lie on the back, feet on
the floor, knees bent, then lift the pelvis till it's in a straight
line with the knees and shoulders (if this is too hard, just put
pillows under the hips).  This will let the uterus fall back towards
where it should be, and allow the pelvic floor muscles to tighten
fully.  When she gets good at doing the contractions, she should
focus on tightening the deep, internal muscles as well as the
superficial ones, as these are the muscles which hold the bladder and
uterus up.

If my descriptions aren't clear, look at a good prenatal or
post-partum exercise reference, such as Elizabeth Noble's "Exercise
for the Childbearing Year".

Jennifer Landels, BA, CE
Vancouver BC