The Backyard Goes On Forever - The Sheldon Creek Trilogy, #1

When Jacqui moves to a rural Australian university town, she expects to get her degree, meet new friends and indulge in the excesses of the lifestyle. What she doesn't expect is to be boarding with an elderly widow and finding out a girl her age died in the widow's backyard the year before. Every day, Jacqui passes through the same yard where Deb died, goes to the same university where Deb went and even becomes friends with the boarders of the eccentric share house where Deb lived.
Learning more about Deb's life, Jacqui begins to suspect the unfortunate death might be much more than that. As the intertwined stories of the small-town residents start to unravel, she fears one of them might be keeping a dark secret.