Is hex hall the first book of series by Rachel Hawkins?

No, Hex Hall is not the first book in a series by Rachel Hawkins. It's actually the first book in the Hex Hall trilogy, which consists of:

1. Hex Hall (2011)

2. The Iron King (2012)

3. The Black Iron (2013)

Rachel Hawkins has written several other books, including the following series:

* The Summer I Turned Pretty trilogy (2009-2010)

* The Royal We duology (2018-2019)

* The Ex Hex (2021)

So, while Hex Hall is the first book in its own series, it's not the first book Rachel Hawkins has written.