Answer:
sad that Cassie had to learn about racism
Explanation:
In "Roll of Thunder, Hear My Cry", Cassie Logan who is the protagonist of the book is a stubborn black nine-year-old girl who learns about racism first hand when she went to Strawberry to shop and has an encounter with the racist Mr. Barnett who leaves the black people waiting for a long time while he attends to the white customers and tells her to leave until she learns her place.
This experience upsets Cassie and Mrs Logan feels sad that Cassie had to learn about racism