I need the wisdom of all you experienced Lactnetters,

Mom gave me permission to share her story.
I have a mom with baby #7 whose milk supply is not sufficient for this
baby.  She nursed 6 other children with no problems, good weight gain,
etc.  She went back to the doctor for a 2 week weight check, and this
baby had not gained from discharge weight.
He was 6# 9 oz at birth 5 weeks ago, discharged at 6# 4 oz, and still the
same 2 weeks later.  Baby had had appropriate wet diapers, but not much
stooling.  Mom had not picked up on the lack of stooling as something to
be concerned about--remember 6 other successfully nursed children ranging
in age from 18-7.  She was shocked by the lack of weight gain.  She had
not noticed anything different with this baby's nursing.  Pregnancy,
labor, and delivery were all normal.  She says she did consistently
exercise through this pregnancy (aerobics and step-master), about
3x/week, but not to excess.  Pediatrician wanted her to supplement at
that first check, but mom asked for a week to try to make a difference.
She nursed more often, but at the end of the 3rd week, baby had only
gained 1 more oz.  At that point she started supplementing with formula,
but really wanted to go with exclusive BF as with other children.  She
rented a Medela Lactina Select pump to try to increase her supply.  After
a week of pumping at least 6x/day, starting out with a 24 hour trial
pumping to evaluate supply, she was getting a max of 5-6 oz/day.  During
the period of having the pump and supplementing with ABM, she went for
another weight check.  Baby had gained up to 7#, increase of 11oz.  But
with her supply not increasing, she returned the pump, and has
reluctantly accepted that she will have to supplement with this baby.
Baby has been willing to go to breast and will suckle 15-20 min on one
breast, but not very long on the other breast.  She has noticed that the
non-preferred breast has been smaller than the other breast all along,
something she did not notice with other children.  She just wants to know
why this happened.   Maybe another baby down the road?  She is 41and
looks fit and vigorous to me.  Any ideas?

Pat Bucknell, IBCLC
Avon Lake Ohio