My neighbor and I share gas and electric meters. Is this legal?

I live in a back house and my neighbor lives in half of a duplex on the same property. We do not have an a-joined wall but we do share meters. When I moved in the landlord had the bills in her name and would mail us both copies so we could pay our share but a year ago when a new tenant moved in she asked him to put the utilities in his name and required him to provide me with copies of the bills so I can pay my share (I pay 1/3 and he pays 2/3). Now he is moving out and the landlord wants me to switch the bills into my name which is making me very uncomfortable. I don't want to be responsible for the gas and electric of the 2 bedroom duplex next door to me when I am only in a one bedroom. So my question is...Is it legal for her to require me to put both properties in my name?