In the novel, Eva perceives her son's cruelty from the start, though it goes unseen by his doting father Franklin (played here by John C. Reilly, everyone's favourite pushover).
When a child had fever, a doting parent would open a can of sweetened fruits to improve the child's appetite — and to help reduce the bitterness of some medicines.
The movie portrays him as a loving, doting husband and father, but he already had two kids with a much older women when he met his wife-to-be Barbara Pedrici.