Chronic Hepatitis B

Hi. I have information about my girlfriend and a not so specific question that requires someone with certain knowledge to give some input.

Six months ago my girlfriend found out she had Hep B. I have the vaciine so as far as I know Im ok. Her mother has had Hep B since before she was born, but didnt know until my girlfriend was an adult. This is because her mother lives in the country of Thailand and there isnt much of a system there.

Anyways to the point. My girlfriend found out she had Hep B about six months ago. She has had the vacine before when she was young so does this mean she has had since she was very young or birth? Or maybe she contracted it from a previous partner?

Anyways the main point is we believe it is a chronic Hep B and nolonger acute because she must have had it for much longer than six months and I have read that if someone has had it for more than six months and it hasnt gone, then it now considered a chronic Hep B that will not go away.

Nowbefore when she found out she had it, she had an amount of 12 million (im not sure what to say.. bodies?) in her blood, but now, the last time we went it was all the way down to 300! thats seems quite impressive. She has been taking Serbivo 600mg pills since she found out, and the docotr reccomended she keep on eating even after the number has gone to zero, for it can come back. So what was this number of 12 million? And is that very bad? The last time it was only 300? She has never done any extensive research on it and just listens to the doctor and is living a happy life, though she does get tired alot and gets sick very easy and often. Headaches, tired body. etc. Shes 28 years old.

Thanks for any input in advance.