The 25-year-old model - who is in a relationship with actor Jason Statham - is very "cautious" about trusting people so is wary about striking up a bond with new acquaintances.
She said: "It takes me a long time to make friends, only because I travel a lot and I don`t trust easily.
"I`m cautious, that`s just something I`ve learnt. I`ve been burnt in many ways and you`re cautious about the people you`ll allow into your life and who you invest time in."
Rosie`s closest friend, Maddie, is training to be a teacher and the `Transformers: Dark of the Moon` star enjoys spending time with someone outside of the showbiz world.
She told Britain`s Elle magazine: "She is not connected to this industry in any way, shape or form, she`s such a breath of fresh air."
Most of Rosie`s friends are people she has known since childhood.
Speaking about her pals, she said "They knew me first when we were jumping in bushes on the way home from a nightclub, aged 14."