Complex sentence: Her first performance was at the age of six, when she appeared in a flower pageant, and at age twelve, she performed in a children's radio production of "The Beggar's Opera", which attracted the attention of KGO.
Split into simpler sentences: Her first performance was at the age of six, when she appeared in a flower pageant. At age twelve, she performed in a children's radio production of "The Beggar's Opera", which attracted the attention of KGO.