Answer: The option that corrects the pronoun usage is the second one: Replace "she" with "her".
Step-by-step explanation: In the sentence provided, the pronoun is functioning as the indirect object, that is to say as the recipient of the direct object ("my only dollar"). Moreover, the indirect object is making reference to another person that is not "I"; therefore, the pronoun cannot be replaced with "me" nor "its" because "its" refers to a thing and not to a person. Furthermore, the indirect object does not make reference to a possession; therefore, "mine" cannot be used either. In that way, "she" must be replaced with "her", which is an object pronoun that can receive an action and makes reference to a person (a female).