Is there a book 2 of hush by Becca Fitzpatrick?

Yes, there are actually four books in the Hush, Hush saga by Becca Fitzpatrick:

* Hush, Hush (Book 1)

* Crescendo (Book 2)

* Silence (Book 3)

* Finale (Book 4)

So, "Hush, Hush" is actually the first book in a series!