Do you think it's OK to refrain from stealing the spotlight from my sister?
Why don't you want to steal the spotlight from your sister?
My sister is very supportive of my stuff and will help me out whenever I do something.
Even though you may receive more attention by stealing the spotlight, it is good that you do not want to steal the spotlight from your sister because it is not okay to do so. You could hurt her feelings after she has been very supportive of you.
Good thinking but my sister is ugly anyway.
Your last statement doesn't track with everything else you've said. You sound a little confused. You should consider counseling to help you navigate your feelings.