Gateways, Book I of The Elemental Chronicles

One cruel night, Victoria’s mother painted a final gateway, a painting that leads to other realities. For years the painting hung unobtrusively on the wall, until Victoria falls into it. Slipping right past the oil, through the canvas and into the world her mother painted, Victoria discovers a beautiful land inhabited by sphinx and minotaur. The people there are incredibly gifted, able to communicate with the natural elements. Turns out that Water is moody, Air demands attention, and Fire is hungry all the time. And Earth? That's where the true power lies.
All the beauty is tainted when Victoria meets Ona, a vengeful leader who discovers that Victoria holds the key to finding the Grandfather’s Weapon, the ultimate device that grants absolute power to the one who can wield it. Victoria must learn the skills of the mage, discover why her mother was guarding the gateway, and protect the Grandfather’s Weapon, or all the worlds in existence will suffer the same fate as Noah’s ancestors.
 
 “Jessica Schaub weaves together mythology and adventure in a brilliant story of friendship. A must-read!” - Liz Konkel for Readers' Favorite
“Schaub succeeds in placing teenagers into a story of mystic powers and magical without her characters losing their modern savvy and their wisecracker-y.” -Chanticleer Book Reviews