Georgia, 29, is among a host of celebrities who have shared emotional tributes to Caroline after she was found dead at her London flat aged 40 yesterday.
Taking to Instagram, the former Coronation Street star shared a lovely picture of herself and Caroline, which was taken as they sat together in a bar.
Georgia went on to explain just how close her bond with Caroline was, adding that she will "love her forever".
In a heartfelt message, Georgia said: "I've never had a friendship like we had. It was so special.
"We helped each other through so much. I am so sorry I couldn't help you see the light at the end of this one Caroline.
I love you. You know this. Always have and always will. You will forever be my sister.
"I am so angry that all this absolute bullying has led to this. If only people really knew how much lies hurt, and how wonderful you really are.
"I love you. You know this. Always have and always will. You will forever be my sister 💜."
She continued: "I can't believe this has happened. I'm not sure how I will ever believe it.
"You will always be in my dreams. Forever love from your little one @carolineflack."
On Saturday evening, ITV confirmed the tragic news that Caroline - who was facing trial next month accused of assault - had been found dead.
A statement read: "Everybody at Love Island and ITV is shocked and saddened by this desperately sad news.
"Caroline was a much loved member of the Love Island team and our sincere thoughts and condolences are with her family and friends."
Her sudden passing has shocked the showbiz world, with dozens of celebrities filling social media with tributes to the star.
Love Island voiceover Iain Stirling, meanwhile, shared a clip of Caroline on Strictly Come Dancing in his tribute to her.
He described Caroline has his "sassy friend" in the sad message.
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