Jessica, 23, a former Miss Lebanon 2010 candidate and Miss Lebanon Emigrant, beat 23 other stunning Australian beauties.
She will now represent Australia at the 2012 Miss World finals in Ordos, China, in August.
Kahawaty, of Sydney, won the competition playing a rendition of Beethoven's Furelisea with a severely injured paw.
She said: ''I had so much adrenaline and thought: 'I'm going to do it even if it doesn't sound so good.
'I took off my cast despite the doctor's orders.''
Kahawaty is on track to receive her Bachelor of Laws and Business (Finance) at the University of Technology, Sydney (UTS). Her modeling achievements include Pepsi Nex Japan TV campaign, 2012 face of Lexus, Maybelline Cosmetics for India campaign, Daewoo for Korea, Jimmy Choo Hong Kong (among others).
Her pageant achievements include Miss Lebanon Australia 2007, Miss Lebanon Emigrant 2008, Miss International runner up (out of 75 countries) 2008.