What is the type of budget you have in mind?
For the three notes together, I can mainly think about Arabian style rose-oud combos, which sometimes have leathery connotations. Examples would be Dior Leather Oud (or even its Oud Ispahan) or Montale Oud Cuir d'Arabie. But these tend to be very expensive, especially the Dior. Arabian perfume houses, which are certainly sold somewhere in London, could have similar inexpensive oils, but I wouldn't know which ones are really good.
For an uplifting rose with cream and musk, my suggestion would be YSL Rive Gauche (or even better Paco Rabanne Calandre, but I think the latter is hard to find). My happiest and cheeriest rose, however, would be Lush B Scent, simple, unpretentious, but very very happy. It's cheap, but I don't know if it is sold in actual Lush stores or only online. In general, Lush gorilla perfumes tend to be very cheery and bright - cheap, but uplifting.
If she feels like whipping somebody's ***, then there's the butch floral leather of Bandit (though it's certainly not very rosy).
cacio