Girl falls asleep on bus and goes to magical land. SOLVED [s]

[Mary]

A girl is riding the bus to school when an accident causes her to lose consciousness. While she is knocked out, she goes to an otherworldly realm where she has to complete some kind of magical quest. I also remember a piece of jewelry or amulet being involved, and I think it had something to do with getting her back to the real world.

[Cheryl]

Heaven Looks a Lot Like the Mall is a bit like your description...

[Mary]

Thank you, Cheryl. That's not it, but I appreciate you looking into it. :)

[Michelle Mulford]

The Seventh Princess? More middle-grade than YA, though.

[Mary]

That is definitely it; thank you so much!