I’ve had acne since I was 12, here are my choices
Make up: Tinted moisturiser (not foundation) and a good concealer. A liquid/creamy concealer on a wand is easiest to blend. Good choice of colours and good blending is super important as badly matched concealer makes spots more obvious.
Budget: I rate the Nivea tinted moisturiser and Revolution concealers (the liquid ones with a wand applicator) for their price
Pricey: I like the La Roche Posay Effaclar tinted moisturiser or the NARS one. NARS radiant creamy concealer is the best I’ve tried - really good shade range and lots of pigment
None of these make me break out more altho it varies from person to person. Bare Minerals is supposed to be excellent for those who react easily, but I’ve never tried it
Not what you asked but my acne treatment recommendations after 30 years of trying everything:
Start with Cerave face wash (the normal/oily one)
and Acnecide cream (weak benzoyl peroxide) over the counter. Be careful as this cream bleaches coloured clothes/bedlinen.
Next step is get Epiduo from the GP (stronger benzoyl peroxide plus adapelene, a retinoid)
If it seems hormonal (comes and goes with cycles) she could try Spironolactone or Dianette - Dianette is contraceptive pill so may not want that so young. But v effective. Spiro is not a contraceptive pill
Next try antibiotics but also have probiotics as they can really mess with gut
Finally and only as a last resort via a dermatologist there is Roaccutane but can have truly awful side effects (depression, suicide, possible effect on sexual development - as well as v dry lips/nosebleeds). I would avoid personally, not least as it didn’t work for me anyway