Backwards Into The Future by Bronwyn Elsmore
Everyone knows you can't go back. Everyone except Mary apparently, because here she is - back in her old hometown. That's because of two women - Kui and Ana. One of them is pushing her, the other is holding back, and between the two there's much to be resolved. The plum tree and the manuka have gone, but a lemon tree thrives. The mystery of the Marakihau may never be solved; but if Ana returns, their friendship and some things from the past can be recovered.