Paul,
Thanks for the question and for taking the time to research the issue.
As a "rule of thumb," it takes about as long to bring a milk supply back
up to the previous level as a woman has been without pumping.  As for
other suggestions, you have hit upon many of them.  I would encourage her
to increase her fluids (non-caffeine type, if possible).  I would also
ask her to take a good look at her day and start the pumping off at a
time is least stressful to her (after a bath?  Or during a good movie?
Whatever works for her).  Prior to pumping, she could try a warm shower,
along with massaging her breasts.  If she does the breast massage, be
sure to instruct her to massage from the areas distal to the nipple down
toward the nipple.  In other words, for example, from her armpit down
toward the nipple, not the reverse.  She should not stretch the breast
skin, as the tissue is very delicate and sensitive.  Another water trick
I've had moms report success with is to soak over a warm basin of water,
with the breasts hanging into the water.  When mom gets some milk, she
hopefully will be encouraged to continue with the pumping.
I find mental imagery works for some moms.  They have to find the image
that works for them (imagining a babbling brook on a warm day seems to be
popular with the women I talk to).
Lots of support and encouragement do wonders...and a reminder that she is
doing the best thing for her baby possible.  No medical magic in the
NICU, no matter how terrific the staff, can offer her baby her own
breastmilk...only mom can do that.
Lee-Ann, RN, IBCLC, in New Jersey (on the east coast of the US)