Blood tests do not always come back positive in someone with Sjogren's
syndrome. The symptoms are many times the only way to identify it. From the
symptoms you describe, it certainly sounds like she has Sjogren's. Especially
if her sister was also diagnosed (as was the case with my twin sister). I will
be attending a seminar on Sjogren's on April 1st. I'll be sure to ask about
milk production.
Judi Lauwers