The Far West (Frontier Magic #3)

Eff is an unlucky 13th child, but also the seventh daughter in her family. Her twin brother, Lan, is a powerful double seventh son. Her life at the edge of the Great Barrier Spell is different from anyone else’s that she knows. When the government forms an expedition to map the Far West, Eff has the opportunity to travel farther than anyone in the world. With Lan, William, Professor Torgeson, Wash, and Professor Ochiba, Eff finds that nothing on the wild frontier is as they expected.