even though she messed up, her reaction made it all okay. That's an artist. She has already reached her maximum and if she keeps on singing like that for another hour, she'll lose her voice for a week. This is where the techniques she learned comes in to help her finish, so good job!
Is she the best musician/artist? Definitely not BUT, no one can deny she’s very lucky AND also work VERY hard in this industry. She also has a lot of other personal qualities that gets her to where she now. There are very good reasons why she’s so successful and I applaud her for all of these reasons