This biography is from her old English site.
It had like a lot of 'fake' made-up information about Ayu.. I think that the TIME article has more accurate descriptions of herself since she is the one saying those things..
http://www.time.com/time/asia/features/ayumi_hamasaki/
SHE HAS NO SIBLINGS. Her father left when she was like, 3, and her mom/grandma are all she had left. Her grandmother died the day of the recording of poker face and her mother's still in Tokyo. :]