SF book ecological theme female author

[baltree]

Series of books (5?) written by female author about different planets reactions to ecological issues. Main character is a human female who travels to a planet in harmony with nature. She becomes immortal via an accident. Breeds with a local alien and deliberately spaces herself at one point, but survives. Visits another planet that only has one tree remaining. Eventually returns to a ruined earth ( Australia specifically) with aliens who are strict enforcers of ecological integrity who want to eliminate Earth for the mistakes we have made. Author? Series title? Individual book titles? Written in the last decade or so.
Thanks for reading.

 

[Suzecog]

It’s the Wess’har series by Karen Traviss, City of Pearl is the first, followed by Crossing the Line, The World Before, Matriarch, Ally and Judge. One of my favourite series.