Complex sentence: Although Overmyer already had a successful career as a nurse, she also was curious to see if she could be a professional musician, and trying out for "American Idol" gave her the best chance to test the waters without risk.
Split into simpler sentences: Although Overmyer already has a successful career as a nurse, she also has an urge to see if a professional music career could be her future. For Overmyer, trying out for "American Idol" gave her the best chance to test the waters without risk.