She Was Going To Marry Him

Hailey staked out this town for three days looking for monster activity and managed to figure out what was protecting Dallin. As Jordan guessed, it was Pepper. 

The hellhound was extremely loyal, following him to work and hanging around outside. She managed to kill a ghoul AND a shifter in the time Hailey was watching and Dallin didn't have a clue. 

He went about his day-to-day life completely oblivious. She had looked into him more since she had his full name and discovered that he had lived in this town his whole life, was single and lived alone aside from Pepper, and ran a nursery that his parents left to him when they moved to Arizona last year. 

After seeing how effective a deterrent the hellhound was and finding out about Dallin's relationship status, Hailey came to a decision. She was going to marry him and live peacefully under his pet's protection.