Barbara,
In the event that retained placenta is not the cause of this mother's non-
production, are there any pschological issues that may be causing her to "hold
onto her milk"?  Is she having any problems in her relationship with the
baby's father?  Is the gender of this child the same as the first - a
longshot, but I've seen a subconcious distancing stuff and reluctance/refusal
to bond with baby because it should have been other gendered.  Anything else
seem to be going on with her?  Don't be afraid to trust your intuition - but
be careful - you may get in over your head if some "old stuff" is what is
going on with her.  When someone with your level of expertise feels stymied,
it is generally some cause out of left field.  Good luck and let us know
how/if it gets resolved!

Gretchen Andrews, BA, LLLL, IBCLC
private practice, Redlands, CA