I agree with the previous posters to not worry about naplan. I am a high school teacher and many of my year 9s are in panic mode despite continually reassuring them it has no impact on their results or lives and they should just try their best. We do one practice exam so that they are familiar with the format and a few practice worksheets throughout the year when it links directly to the curriculum. Teachers and schools are not supposed to teach naplan, they are supposed to teach the curriculum.
I thought I'd also respond to the people worried about high schools requesting previous naplan results. My school certainly does this but it is not used to determine who is accepted and who is not, or even which class they will be in. We use it once students are already accepted to get an idea of whether a student may need support in year 8. As you can imagine high schools have students coming from a variety of primary schools, all with different levels of understanding and so it helps us to have as much information about our students as possible so that we can identify "possible" gaps in learning or "potential" challenges in learning or even students who "may" need to be extended. Please note that we never make decisions about our students based on naplan results because as others have said it was one test on one day a long time ago, but it can still be useful. I hope that sheds some light on why a high school would request naplan results!
Me - 30, Dh - 38 ttc #1 since June 2011
natural bfp June 2012 - mc 5.5 weeks; 5 cycles clomid; 2 unsuccessful ivf.