sorry not hep b but autoimmune hep...
livers can detereorate quickly...depending on a lot of things...with or with out the virus'...alot of us here don't know that much about hep b but, we know more about hep c at this forum...can you find more info on hep b to see if this is common?
We can only guess an answer on this, since we are a patient to patient group. Have you asked the hepatologist these questions? s/he is more familiar with her case and can best answer your questions.
One thing to bear in mind about biopsies is that it is a small tissue sample of a rather large organ. The possibility exists that there was more damage in one area than in the other, at the time of the first biopsy, but the sample came from the least damaged area. This bx might have a sample from the more damaged side. It can be difficult to say for sure if there was progression or if it was a tissue sampling difference. It can also be a grading/pathology difference since the reading is done by a pathologist. Get in touch with her dr and ask about these concerns.
GL to you both