This spiraled. And I'm still not entirely certain that I have an answer to the question.
While I originally thought of Love at First Bite as a YA series (to which I have been given varying opinions), this is a difficult question for me to answer, considering that I was never really a YA reader.
When I was growing up, I read The Once and Future King, Mary Stewart's Merlin Trilogy, and her follow up with Mordred; then I read Vertical Run, which might be the best thriller I've read. I think the family tradition of Die Hard as the family Christmas movie started when I was ten years old. During my high school freshman summer camp, I brought The Three Musketeers as well as Les Miserables, not knowing I would be forced to participate in "organized fun." Once I left that particular subsection of Hell, I finished Les Miserables in a week.
Suffice it to say, I was a very strange child.
So, when I started with Honor at Stake, my idea of "YA" was based on a concept that "Young adult refers to the vocabulary, not the content." I was then informed that content in YA novels included sex, violence, and rape....
If you are not shocked by this, you probably have a better idea of what the YA market has right now than I do.
The discussion this prompted on my Facebook page is long and varied. Even suggesting that 80s fantasy has been relabeled as YA, including Dragon Riders of Pern.
At the end of the day. the most accurate response thus far probably goes to my original acquisitions editor for Honor at Stake, Erin Lale. The short version is that it "means different things to different publishers," but "the YA label only means it's being marketed as for teens. If you are looking for safe content you have to know which publishers have that as part of their criteria."
Best line goes to one of the comments in the thread: YA is all in the marketing at this point. "Is your book YA?" might as well be "Can we market your book to YA?"
An assessment that is probably also true.
Circling back to the original topic, "Is Love and First Bite" YA friendly, the answer is ... maybe, depends on who you ask. In all three books, there are two lines of dialogue that are probably not child-friendly, but I had already learned on the playground of my Catholic grammar school before I even knew what the words meant. They are both in Murphy's Law of Vampires, and it's cursing at a demon. Because if you can't use profanity at a demon, who can you use it at?
I think the answer for Love at First Bite is in JD Cowan's review of Murphy's: "combines romance, horror, thriller, fantasy, comedy, and science fiction."
In short .... maybe?
Look, at the end of the day, I hate to say this, but ratings in novels have become so subjective these days, the only proper answer for a parent looking for books to buy their kids has to be "Read it before you pass it along." It's really the only way to know to be sure. It's just like television.
Video games and films, at least, have guidelines and methodologies for their ratings. There are reasons, even if their reasons don't seem reasonable. If a video game is M for Mature, that's because there will be cursing (Halo, Legendary level) or people being cut in half (Mortal Kombat). If a movie is rated R, that's because there's either cursing, sex, or things that parents generally don't want to explain to their children. Heck, The King's Speech was rated R because they counted the cussing in that film. It was a straight drama, but it had "more than allowed" number of F's, kind of like the internal dialogue of Samuel L. Jackson's brain, and for similar reasons.
So, everyone, here's my question to you: where does "Young Adult" end and "New Adult" begin? Yes, NA is a thing now. Don't ask me to explain it, I'm not sure I do. What do you see as "YA" that isn't usually considered as such?