The 21-year-old, who is currently studying at Cambridge University, played the part of Polly in the original instalment of the franchise in 2007.
Contactmusic quotes Cole as saying: "It was fun. There wasn't really much pressure. I didn't really take it very seriously. I wasn't really committed to the character. I like the idea of being a model and playing a geek.
"I quite liked taking the p*ss out of the fact I do study a lot. It was just a bit sardonic."
The forthcoming sequel St Trinian's: The Legend of Fritton's Gold is due in cinemas on December 18 and stars Rupert Everett, Colin Firth and David Tennant.
> Lily Cole: 'Ledger taught me how to act'