The singer flew to the island on July 12 to celebrate her 24th birthday and reaching a settlement in her leaked sex tape case against ex-boyfriend Justin Edwards.
She was meant to perform at GuilFest in Surrey yesterday (July 14) but cancelled just half an hour before her scheduled appearance after falling ill.
Organiser Tony Scott told the Daily Mail: "We got a message from Tulisa's team just beforehand saying she was unwell and could not make it.
"They said she was really sorry and would love to come back next year. I think GuilFest is one of Tulisa's favourite gigs and this would have been her third time in a row.
"I think she was genuinely upset at not being able to perform but if somebody is not very well, they are not very well. You have to be 100% when you get up on the stage."
Tulisa has since taken to Twitter to apologise for her absence, writing: "So sorry I had to cancel at Guilfest guys. I was really unwell. Hate letting down my fans but I genuinely couldn't perform. Im on the mend X."
Take That tribute act Take Fat took her place at the event, which also featured artists including Cher Lloyd, Olly Murs and Stooshe.