Which Cerave does she use? The Foaming face wash or the Hydrating face wash. I had really oily skin as a teen. It's a little better now and I can only use the Foaming one.
Also, if her face is oily, that is just the type of skin she will have to deal with. Try not to use cleaners that are too harsh thinking that they will be better at removing oil. More likely they will trigger her skin to produce more oil. So ramp up the harshness of your facial cleaner slowly. To control oil, she can use blotting papers, a light dusting of face powder, or some sort of mattifying face primer. I'm not up to date on the latest products as my oil production lowered significantly when I entered peri (yay!)
A BHA product of some sort at a frequency that doesn't overly dry out her skin should help keep the small pimples away.