The Perfect Horse (Book #1 in the Horseshoes/Kestrels Series) by Patricia Leitch

When 10-year-old Sally Lorimer moves to Kestrel Manor, a rambling old house in the country, it’s a dream come true. The manor has a stable and fields, and at last Sally will be able to own a horse. She soon discovers that the right horse isn’t easy to find and, after an embarrassing fall, must also discover the courage to ride again.