A good skin routine at this age is great to establish. If she is just starting to get a little oiliness and occasional pimple I would suggest she use skin care that is non comedogenic and non oily as this could aggravate acne otherwise.
She should protect in the morning from oxidative damage with non oily broad spectrum sunscreen such as le roche posay (the bb formulation is popular) and underneath this use a hyaluronic acid serum with vitamin b for immune protection as that will provide hydration without oiliness.
At night she could start introducing active skin care slowly-a vitamin a formula slowly first if she is a bit sensitive then add in a keratolytic ( Aha Bha ) next. If she gets any more acne she may need an appointment for prescriptive medication topically or orally.
The aliangé Purity range with the Probiotic Masque is a good regime for her !