2 Books Found

Based on your description:

"read this book in primary/elementary school in Australia in the late 1990s. I would assume the author is Australian as the book is set in the Australian bush. The protagonist was a young teenage girl and she writes the story as she is laid up in bed with two broken ankles (or could be broken legs). She is telling the story of how she came to break her ankles and the gist is that she has been running away from two adult men (I don't remember what their motivation for chasing her is). She describes one of the men as having "dunny brush hair" (dunny = toilet). At the end we learn that in a moment of escape from the men she jumps or falls into an opened and recently cleaned septic tank and lands hard on the concrete bottom?"