Simplify the following text for a Grade 13 native English-speaking person.
Original: Gerrard sings many of her songs , such as Now We Are Free , Come Tenderness , Serenity , The Valley of the Moon , Tempest , Pilgrimage of Lost Children , Coming Home and Sanvean in an idioglossia ( an idiosyncratic language ) that she has developed since the age of twelve .
Simplified: Gerrard sings many of her songs , such as Now We Are Free , Come Tenderness , Serenity , The Valley of the Moon , Tempest , Pilgrimage of Lost Children , Coming Home and Sanvean in idioglossia that she has developed since the age of twelve .