The present perfect is used to emphasize that the past action has present consequences. "She has gone there" does not imply that the person is no longer there. For example:
Q: Why didn't your mother answer the phone?
A: She has gone to the store.
Regardless of whether the sentence is a question, the present perfect should only refer to past actions that have ongoing consequences in the present. The simple past can refer to any past actions. For example:
I heard that your mother took a trip last summer. Where did she go?
I heard that your mother is out of town. Where has she gone?
As the present perfect is used for emphasis, the simple past can often be used instead. For example, there is nothing wrong with:
I heard that your mother is out of town. Where did she go?