There are 1 book by Mary Erin O'Brien on BookOrb. A strong starting point is Accidental Pilgrim (2014). The bibliography below is in publication order, with series grouped in reading order.
Standalone books
Frequently asked questions
How many books has Mary Erin O'Brien written?
BookOrb lists 1 book by Mary Erin O'Brien.
Where should I start with Mary Erin O'Brien?
A good starting point is Accidental Pilgrim (2014).
What is the Mary Erin O'Brien books in order list?
In publication order: 1. Accidental Pilgrim (2014).