Complex sentence: Gia is a leader in some ways, as well, and performed in a band with Stephanie and Kimmy that failed miserably because the girls paid more attention to their appearance than to rehearsing.
Split into simpler sentences: Gia is a leader in some ways, as well. She performed in a band with Stephanie and Kimmy that failed miserably because the girls paid more attention to their appearance than to rehearsing.