A child who does not do good in school may need extra attention from parents at home.

Explanation

The corrected version would be:"A child who does not do well in school may need extra attention from parents at home."This is the error. The correct adverb to modify the verb "do" is "well" instead of "good." "Good" is an adjective, and in this context, an adverb is needed to describe how the child is performing.