Australian crime fiction writer, Chris Hammer (b. 1960), has a series of novels featuring an adoptee, Nell Buchanan.

Nell is a homicide detective partnered with Ivan Lucic. They feature in Treasure & Dirt (2021), The Tilt (2022) and The Seven (2023).

The most recent book in the series (which can be read as stand-alone novels) is The Valley (2024).

During what seems to be a routine murder investigation, Nell finds out the victim is related to her.

From the publisher:

“What did take place in The Valley all those years ago? What was Nell's mother doing there, and what was her connection to troubled young police officer Simmons Burnside? And why do the police hierarchy insist Ivan and Nell stay with the case despite an obvious conflict of interest?”