I thought hepatitis is caused by one of several viruses?
If that is the case, no antibiotic on Earth will have any effect. If an antibiotic did work, then she had a bacterial infection, not a viral one.
Hepatitis is transmitted through food and drink (Hep. A) or exposure to body fluids (Hep. B & C). Hep A is the least dangerous and usually clears up quickly, whilst B & C can have long term effects on your health, particularly if they go untreated.
Just living with someone won't give you any variety of Hepatitis - you would need to have been exposed to their body fluids (for example, by having penetrative sex, or sharing needles with them) in the case of B & C, or to have eaten food prepared by them under unhygienic conditions in the case of A. I am guessing that these scenarios are, by and large, unlikely. Living in the same house as her will not result in you contracting the illness, any more than living in a house with someone who is HIV positive (as I did, for a couple of years when I was younger) will result in you developing AIDS.
If it was a bacterial infection, then she has probably recovered from it, and is no longer infectious, in which case there's nothing to worry about. If it was hepatitis, then the exercise of normal hygiene precautions should prevent transmission of the virus to you. Does she prepare your food? That's the only scenario that I could possibly think might result in transmission of the Hepatitis virus to you, and it would be the least dangerous strain.
I am not an expert: if you're in the slightest bit worried about things, you should go and talk to your GP and s/he will pass you on to an expert if s/he thinks that there is any risk you might have contracted the virus, or need further counselling.