Andrea Carter and the Family Secret (Circle C Adventures #3)

Andrea "Andi" Carter returns in her third nail-biting adventure. Even after dealing with escaped convicts and wild horses, Andi isn't prepared for her latest surprise: a sister she never knew she had. Katherine left the family when Andi was just a baby, and a heap of trouble has followed her now that she is back. Andi finds herself not only dealing with Katherine's sudden appearance, but also a mysterious drifter named T. J. Silver, who has a lot to hide.