What has the author I M Purdy written?

It seems you might be thinking of Isabel Allende, a renowned Chilean author, not "I M Purdy".

Isabel Allende has written numerous acclaimed novels, including:

* The House of the Spirits (1982)

* Of Love and Shadows (1984)

* Eva Luna (1987)

* The Stories of Eva Luna (1989)

* The Infinite Plan (1991)

* Paula (1994)

* Daughter of Fortune (1998)

* Portrait in Sepia (2000)

* The City of the Beasts (2002)

* The Kingdom of the Golden Dragon (2004)

* Island Beneath the Sea (2005)

* Inés of My Soul (2006)

* The Japanese Lover (2010)

* The Sum of Our Days (2014)

* The Master of the House (2017)

* A Long Petal of the Sea (2019)

Note: It's possible there's an author with initials "I M Purdy" that you are thinking of, but they are not widely known or published.