I'm not a children's writer or reader myself, but I have to join in the chorus here and say that the premise is adorable. I think that alone makes it a solid win. Also, I enjoy the original spelling of "Isabella," if only because I think young children might have an easier time reading and saying it. I haven't read the Twilight books, but I'm pretty sure the target audience for that series and this one would differ greatly, or at least by ten years. No one will see the title and what I imagine the cover to look like and confuse the two, so I don't think you need to take lengths to "prove" it's not a knockoff.
Eight year old Ysabela just knows her life will be perfect once she finally gets her fangs!
As someone said before, I actually like the exclamation point here a lot. I think the only "problem" with exclamation points is that they can come off overeager (especially if used too frequently) or obnoxious (if used in the wrong places) but I think this one just makes the premise sound cuter.
She’s thrilled to be starting the third grade with her friends Betha, a witch, and Jack, a werewolf. After all, she’ll officially be one of the big kids taking classes in one of the towers of the magical school deep in the woods.
You might consider giving the name of this school here. It might not be necessary, but I think a good name for the school here will make the world feel more whole. She’s thrilled, (you need a comma here) that is, (and here... I think) until her parents don’t let her walk to school by herself, and her teacher assigns her the seat next to Talia de la Nuit, her obnoxious classmate who thinks she's so mature just because she has her fangs already.
Ysabela is determined to show everyone how grown-up she is. I don't think you need this. The next sentence illustrates her feeling of being left out and implies that she wants to be grown up. Soon Betha discovers her magic, Jack finds his howl, (missing comma) and Ysabela is left behind as everyone seems to be growing up without her. When Ysabela finally gets her fangs, she discovers they come with (would "come AT a terrible price" be better maybe? Does it matter?) a terrible price. A lisp! Rather than stating the end of the story so plainly, I'd try something like: But with a little help from her (friends and) family, she'll learn there's more to growing up then just getting a set of fangs.
YSABELA VAMPIRELLA GETS HER FANGS is a 10,000 word chapter book aimed at readers of Junie B. Jones and The Magic Tree House"House" needs to be capitalized here as it is part of a proper noun, also you might need to italicize both of these titles series of books who may want something a bit offbeat but aren’t quite ready for Goosebumps (I don't think you need this part.). This is the first book in a planned series.
So you won't strain your eyes from my (much too) wordy comments, I think that ends up looking something like this:
Eight year old Ysabela just knows her life will be perfect once she finally gets her fangs!
She's thrilled to be starting the third grade with her friends Betha, a witch, and Jack, a werewolf. After all, she'll officially be one of the big kids taking classes in the (a name of the tower, perhaps?) at the (NAME OF SCHOOL). She's thrilled, that is, until her parents don't let her walk to school by herself, and the teacher assigns her the seat next to Talia de la Nuit, her obnoxious classmate who thinks she's so mature just because she has her fangs already.
Soon Betha discovers her magic, Jack finds his howl, and Ysabela is left behind as everyone seems to be growing up without her. When Ysabela finally gets her fangs, she discovers they come at a terrible price. A lisp! But with a little help from her friends and family, she'll learn there's more to growing up then just getting a set of fangs.
YSABELA VAMPIRELLA GETS HER FANGS is a 10,000 word chapter book aimed at readers of
Junie B. Jones and
The Magic Tree House series of books who may want something a bit offbeat. This is the first book in a planned series.