Chester zoo is my 'local' zoo and although they do have a young giraffe her name is Tula. Margaret was born back in 2008, had a set-back for a short while but recovered from that and was/is fine. She moved to London zoo in 2009.
You can see part of her story here http://www.youtube.com/watch?v=VAykBTxgaBk. (Sheba, the elephant featured in the video sadly died earlier this year aged 56.)