Zander the Great.

Mamie, an orphan girl who was abused in the orphanage, is taken in by Mrs. Caldwell, a kindly woman with a young son named Alexander. Mamie hits it off with the lad, and nicknames him "Zander". When Mrs. Caldwell dies, the authorities decree that the boy must be placed in the same orphanage where Mamie was mistreated. Horrified, Mamie determines to see to it that the boy will be spared the same treatment that she had to suffer.