How do I stop my friends from sharing my facebook photos on their profile?

[pri✍]

If she can see the pic & she is your FB friend, I'm afraid you can't prevent her to share your pic. What you can do is, prevent that shared picture be seen by her friends. So set the audience for that picture to Friends ⇨ thus only your friends who can see it.

Or better yet,
1. set it to Custom, then on "Share this with" to Friends ⇨ thus her friends can't see it and uncheck the "Friends of those tagged:" in case the pic was tagged; but, don't forget to
2. In Timeline and Tagging Seeting ➤ How can I manage tags people add and tagging suggestions? ➤
Review tags people add to your own posts before the tags appear on Facebook? ➤ ON ⇨ thus need your permission whether others can tag your pic. You know, tagged picture is also seen by the friends of those tagged.

Hopefully this solve your problem.
(the underlying: I bet you know, your aunt loves you & proud of you so she wants to show you to her friends.)