Leslie - some suggestions:
*Check with the mom by asking directly if she is giving water or
tea (or anything besides the admitted solids). For some reason I
can't really grasp, moms seem to think that water is like air....
*Try suggesting more hindmilk - that is, a longer time on one
side, or even one-sided nursing every feeding.
* Try to get the mom to rest more. "Stress" is *very* subjective,
and of course she could be "stressed" by going back to school,
but I have seen moms handle a heckofalot more stress than that
and manage quite nicely with supply. I tend to have a feeling
that she's trying to stretch herself in other ways, too. Try to
get her to see that the baby is more important, so she has to
take good care of *her*self for the *baby's* sake. This is in
what I call LC shorthand - I'm sure you get the idea without all
kinds of qualifiers......

*What is your impression of the strength of the baby's suck?

I'm sure that others will come up with lots of good suggestions.
Best of luck. Judy Knopf in Israel