The Faire Folk Saga by Gillian Summers, an award-winning Young Adult series.
Overarcing premise is that Elves, Fairies, and other assorted beings are hanging out in plain sight on the RenFaire circuit. (Ya think?)
Plot line involves the adventures of 15 year old California mall-rat Keelie Heartwood, who is sent to live with her father on the Ren circuit after her mother is killed. Turns out Dad is a high ranking elf and Keelie stands to inherit a great deal of magical power. Oh, & her dad's cat just might be a fairy in disguise.
First book is The Tree Shepherd's Daughter. Series is currently up to 5 books with more to come.
That sounds kind of fun. What's the reading level? I know you said young adult, but it it dumbed down or at least at a high school level?
Written for 15 & up but an easy enough read that younger teens & tweens should have no problem. Little bit of teen girl angst but not all that irritating. :)