The Sweeter Realm - Stefan Scheuermann

In this, the second book of The Swan Knights Trilogy, Verena, a teenage girl from suburban America, finds herself entwined in an ancient enterprise to protect the Holy Grail. She becomes the latest in a long line of Swan Knights — the descendants of the Grail Knight Parsifal, sworn to protect the portal to The Sweeter Realm, where the Grail has been hidden for centuries. The portal calls for Verena and pulls her through, into the Sweeter Realm.

In The Sweeter Realm, Verena is declared Queen of the Land and Shallow Waters, because of relation to the Swan Knights. She meets friends and enemies in her attempt to adjust to her new life. She learns to live, love, and fight like a Queen of the Sweeter Realm, as circumstances take her life beyond any of her previous fantasies.