Whitney Houston's daughter Bobbi Kristina Brown has defended herself against online jibes about her weight. The 21 year old, whose father is Bobby Brown, has been bombarded with abuse on Twitter.com after uploading several snaps showing off her extremely slim figure. Now Brown has hit back at her critics, insisting she is naturally lithe like her late mother. Taking to Twitter.com she writes, "I am my mother's child! Have you ever heard of a fast metabolism? Damn, lol (laugh out loud), it's incredible how the world will judge you 4 any & everything. (sic)" Her husband, Nick Gordon, adds, "My baby is perfect the way she is. And for the record she was made that way why change I know she is beautiful." Houston was criticised by fans in 2001 when she performed at a Michael Jackson tribute concert looking worryingly gaunt.