Air: Merlin's Chalice. Children of Avalon, #1

In one day Scai has gone from an ordinary outcast in her little Welsh village to learning that she is a member of a magical people called the Vallen. Left on the church steps by a strange couple to be raised by the town priest, she knows nothing of her history-or her abilities. Did she really stop the rain just by wishing it to stop? But she is determined to learn all she can. Travelling alone to England to find her family seems to be the only way she's going to find the answers she seeks.
Her journey leads her to the funny old knight Sir Dagonet, the handsome squire Dylan and the fiery Bridget. Together, Scai, Dylan and Bridget are the long awaited Children of Avalon, destined to save the world from Lady Nimuë, formerly known as the Lady of the Lake-unless she kills them first. Along the way, Scai finds magic - both in the wind and air that she can control at will, and in the sweet ache of a first love that she cannot.