neatly
The adverb in the sentence, 'She writes neatly' is 'neatly', and it is located right before the verb in the sentence, 'writes'.
An adverb is just a verb that describes another verb. It is the amalgamation of an adjective and verb. Adverbs always end with '-ly'
The adverb in the sentence is defined as the adverb of manner because it describes the manner with which the verb was being completed.