Good is an adjective (good performance). Well is an adverb when it modifies a verb (speak well). The use of the adjective good in place of the adverb well to modify a verb is nonstandard and especially common in casual speech.

The adverb well modifies the verb had done.

Confusion can arise because well is an adjective when it modifies a noun or pronoun and means “healthy” or “satisfactory” (The babies were well and warm).

As an adjective following the linking verb did feel, well describes Adrienne’s health.

Bad is always an adjective and should be used to describe a noun; badly is always an adverb and should be used to modify a verb. The adverb badly is often used inappropriately to describe a noun, especially following a linking verb.

The adjective bad is used after the linking verb felt to describe the noun sisters.