Taking the painting and replacing it with a replica - unless it was given to her in a decree, a clear intent for fraud,
I hadn’t thought of the replica angle as fraud. The article doesn’t state whether she was trying to cover up the removal, or just put something in its place. If she thought her replica was nearly indistinguishable from the original, you’re right, its fraud.
Maybe the difference was obvious—different frame, maybe she wasn’t that good an artist, anyway.