Hi, I am suddenly new at teaching too. I live in Madrid and have had two students for about 2 years. All of a sudden, word of mouth went zipping around and I have 5 more, including two 8-yr old girls. I am self-taught, unqualified and really just a hobbyist.
The 8-yr old girl prospect frightened the heeby-jeebies out of me and when I saw the method books they had been using (given compliments by several previous commentators on this thread) I recoiled at the patronising, infantilised tone used. The books are perfectly fine for explaining, but don't seem to tap into the well-spring of AMBITION that is really the motor for learning. So I decided to step on the gas a bit, Fur Elise (complete) for sister1, Bach Gavotte for sis2. No pictures of smiling elephants, hot-air balloons or witchs' covens, and difficult stuff for those tiny hands.
One month later I haven't been thrown out, and the girls have lit up like anything.
Go for the ambition. Drive your student. Choose pieces that are deliberately beyond what they can do. You are only going to be their teacher for a year, so there isn't even time for a method. Either you try to cram it all in to 8-9 months or you leave them half-methoded as they move to their next teacher. I recommend you go for a piece or three. After all, all piano method has already been written down, and by the greatest musical minds who ever lived (Chopin, Schumann, Brahms, Beethoven...). It's in their notes. There you can find everything.