Actually, it's Axl's stepsister. When his mom remarried to that Bailey guy and changed Axl's last name to Bailey, they had two kids, Amy and Stuart. So they had a different dad. Wish they had a pic of Mr. Bailey though.
From:
Savrin
(Wed 24 Dec 2008 22:24:08 EST)
Amy is his half sister, not his step sister. I understand that Mr. Bailey adopted both she and Axl, and together with Sharon Rose, they had Stewart.