Julie is right. Do what is comfortable to you in your range and something you can sell. My dd learned this summer that it's now about belting or showing off, but rather in finding the bars of a song that really show off personality. Start off strong and confident and end strong and confident, even if it means not doing the bars of the song that show belt range.
It's all about what song suits you as the performer. Don't worry about what anybody else says. If you can sell the song, you're doing good.