Jill,
IMHO, you did your job.  Plain and simple.  The client asked for information,
you gave it.  You provided her with relevent, factual information on the
importance of BF, AND gave her a guilt free out if BF wasn't for her.
It sounds to me like the clients mom may not be a BF supporter and got upset
when the girl gave her the info you gave her.  Sadly, this happens all to
often.  The girl prob'ly got upset at her mom being upset and unsupportive.
 The thing to do here is to have your unsupportive boss talk to the client
herself and ask her opinion, without the mother around of course!
It is very sad that your boss is not supportive of you.  I am sure that you
make a big difference with the people you help.  Keep doing what you're
doing.  And let the peolpe who have the problems deal with them.  They have a
prob, not you!
When you *give your side* try to tell exactly what happened in as neutral a
manner as possible.  Try and not let yourself get caught up in a defensive
mode.  This will, IMHO, look better for you and also be more professional.
 After all, that's what we are!
Good luck!
Jay