Nipple shields work best with motivated moms.  This mom does not sound the
least bit interested in working at it.  If a nipple shield provided her with
an instant fix then it would be worthwhile (even day 1 or 2) as it might be
the only way the baby has a hope of receiving any breastmilk.  However, you
described large, soft breasts -- and these are the most difficult to cope
with as the shield sinks into the breast tissue.  Mom has to be positioned
creatively to avoid this little glitch.

I always try a shield after all else fails (after all -- if can't get baby
feeding at breast in that first visit I may not get another shot).  When it
works the success is so encouraging to the mom compared to having to go home
to pump and somehow supplement.  When it doesn't work I cross my fingers that
mom will be willing to do the necessary to safeguard her supply until the
baby will latch.

Joanna Koch, IBCLC in Los Altos, Ca