Guardians of the Fae by Elizabeth Hartwell

One halfling female. Four Guardians. A dark secret that could destroy everything.

Paranormal detective Eve Carter knows things. She’s always had uncanny gut instincts. When a run of supernatural murders take place, Eve thinks she may be the only one who can save her once idyllic hometown from the dark threat.
What she doesn’t expect is four sexy Fae warriors to save her from a vampire attack.
Guardians Noah, Tyler, Jacob and Cole have spent centuries protecting the Fae, so when there is a breach of the veil between the realms, they are ordered to investigate the disturbance.
But what they find is something no one ever expected. A halfling, a human with the gift of the Fae.
Eve has vowed to put an end to those who are committing the murders, and persuades the warriors to become her protectors.

But as the Fae males try to shield Eve from the dark forces moving against her, they slowly begin to realize that the real horror might not be those who are committing the murders . . . but Eve herself.