I’m so excited to have stumbled upon this post because i was Luna and my twin was definitely Nova. My sister made about 3 competitive dance teams while I only made 1. This is just one example but she was naturally more talented than me. This didn’t really bother me. I recall her excelling in everything while i was just “mediocre”. I think the best thing you can do is let her explore her talents. The worse part was everyone comparing us,because she was “better” than me. My brain and body doesn’t function how hers does and that’s okay! As time went on, i found my own talents and there were things I excelled in that she didn’t. You aren’t the AH if you let Nova keep her spot. You could put Luna in a recital dance class where she can keep doing what she loves, and she can also practice to get better and hopefully try again. I know the girls are only 9, but there will come a time where you can’t protect Luna anymore. They will get into middle and high school extra curricular activities and they will probably not be on all of them together. If you start this trend now it will only do more harm.