Final answer:
The correct pronoun to use is 'she' because it serves as the subject of the verb in the comparison 'No one types as fast as she on a word processor.'
Step-by-step explanation:
The correct form of the pronoun in the sentence 'No one types as fast as (she, her) on a word processor' is she. In this context, the pronoun is the subject of the verb 'types', which implies that it should be in the subject form. Therefore, the complete sentence should read, 'No one types as fast as she on a word processor.' We are comparing the subject pronoun 'she' to 'no one', which also acts as a subject in this sentence.