Simplify the following text for a Grade 7 native English-speaking person.
Original: Billie ( she was known at the time only by her first name ) was the first and youngest British female artist to have a first single debut at # 1 on the UK pop charts .
Simplified: Billie ( she was known at the time only by her first name ) was the first British female singer to have a first single start at # 1 on the UK pop charts .