Speaking as someone whose had to watch for breakouts all my teen & adult life I'd say Obaji do one "Clearderm"I think it's called or similar. If you google Obaji it should come up. Used to only be sold in private cosmetic surgery places like transform but thanks to Ebay it's a fraction of what it used to cost. (I was quoted about £350 for the set at Transform OUCH! Didn't buy it there but do use the Rosaclear for acne rosacea moisturiser & it's been good. Range gets rave reviews.
She can go to the docs & get a prescription for a gentle anti biotic lotion now called Dalacin, great for breakouts, blackheads & hormonal acne
a nice light cream to moisturise if required in addition to the obaji, deffo not an oil rich one. Linda Lusardi's creams on Ideal World are very good, bit pricey but they are quality and totally non greasy altho she may just want to use the day one & not the night as that's richer.
Hope that helps xx.