The cake slices, and white cup are all G3, and are re-used on loads of different sets
Boppers belong to Wing Wishes Minty I think
Hat belongs to Penny Candy
The arch, cake (it gets bigger if you put a ponies magnetic hoof on the heart) veil and shoes belong to Crystal Princess Bride
Oven goes to Cotton Candy Cafe
Mirror goes to the Celebration Salon.
I think anyways - colours are a bit off on my monitor