The present perfect (e.g., has gone) places focus on the event, not the time when the event happened. As a result, the meaning is expresses could be 'before' or 'recently'.
2. She's gone to the prison.
a) She has gone to prison before, and is on her way there now She is not in prison at the moment.The simple past places focus on when the event happened, which is why time can be specified:
b) She has recently gone to prison, and is still there now.
1. She went to prison... But when?
a) She went to prison 5 years ago and is no longer there now.The simple past and the present perfect can express the same meaning; however, with the present perfect, having to state or assume the time something happened is not necessary, because the perfect focuses on events, not time. So, for example, if someone asks you if you read the latest Harry Potter book, you could answer, "Yes, I have" or "No, I haven't", both of which refer to the event, read a Harry Potter book, not to the dates that you actually read it, because you wouldn't know or it'd take time to think about.
b) She went to prison 5 years ago and is still there now.