I read your query and I understand your concern.
That value means that she is the carrier of the virus for
Hepatitis B, meaning the has contracted the virus in the past usually by blood or semen, hasn't had any signs or only minor ones she has ignored, but the virus hasn't been eliminated, it is persistent in her body.
The fact her liver functioning is normal means the disease is not active for the moment. However, while she can remain like that for decades, there is also the chance of her developing
chronic hepatitis in the future, so periodic liver function tests are indicated.
Hepatitis A vaccination is recommended.
Another issue is spreading the infection to others. So you her husband should be tested as well as your other kids if you have any.
Also there is the risk that during birth (not
pregnancy) the infection could be transmitted to the newborn, you should inform the medical staff about the results and the baby should receive vaccine upon birth and two additional doses during the first year of life as well as hepatitis B immune
globulin upon birth.
I hope to have been of help. Feel free to ask further questions.