Read the text and determine if the sentence is true:

Gillian Plowman is an award-winning English playwright. She is the author of more than 20 plays. She won the 1988 Verity Bargate Award for her play "Me and My Friend". Originally staged at the Soho Poly, it was later revived at the Chichester Festival and at the Orange Tree Theatre. In 2008, the Oval House Theatre staged her play "Yours Abundantly, From Zimbabwe".

Sentence: Gillian Plowman is 58 years old. 
It's impossible to say