Re: What the name Jayla means?
More often than not, parents give names to their children based more on the pleasantness of the sound, than on the actual meaning of the name. And many new names are "invented" because of this. Your friend in high school may have been given the name "Jayla" simply because her parents liked the sound of those combined syllables -- I couldn't find any meaning for that name in any of my sourcebooks (perhaps someone else here might find it).
I would guess that "Jayla" may be a combination of a couple of different names, such as "Jane" and "Kayla". Many new, and lovely (at least for female children), names are coined by parents experimenting and making interesting combinations of existing names.
-- Nanaea