Final answer:
The appropriate intensive pronoun to complete the sentence is 'herself'. Using the intensive pronoun emphasizes that she is capable of doing it on her own.
Step-by-step explanation:
The appropriate intensive pronoun to complete the sentence is herself.
So the sentence would be: You don't need to help her because she can do it herself.
An intensive pronoun is used to emphasize or intensify a noun or pronoun. In this case, using the intensive pronoun 'herself' emphasizes that she is capable of doing it on her own.