After the "Far From Home" quest is completed, Serel moves to the Brackenbury District - standing by the fountain with some flavor text when spoken to.

 

Upon leaving the Sanitarium after the completion of "The Man Who Waits", assassins ambush the party. However, about half of the assassins head directly for Serel, attacking and killing her before targeting the party. 

 

This bug was also reported in the Backer Beta in this thread.

Hehe, yeah, had that happen too, poor girl.

Just to addandum though, no, that was NOT in the beta. The entire city of Defiance Bay wasn't in the Beta. The post is also made post-release, just someone posting in the wrong location on the forums :/