You should introduce her to the Oil Cleansing Method. Its great for dry, normal and oil skin. It just depends on the oil formulation. I would suggest 60% jojoba and 40% castor oil for an oily skin formula. A toner made from 40% witchhazel and 50% rosewater and 10% glycerin.
Makeup remover:
Massage oils on face and wipe off with microfibre cloth.
Deep Cleanser
Massage oils on face for 1/2hr, usually while watching tv. Occasionallu massage oils into your face for that duration. Squirt some witchhazel/rosewater toner into a couple of cotton pads and wipe it off. The oils will dissolve the sebum on the skin and the oils that may be clogging pores. The massaging action will remove dirt trapped in the pores and dead skin as well. The toner will take the excess oils from the skin but leave your face wickedly smooth and well moisturized.
Store bought cleansers for oily skin only perpetuate the problem. It removes the oil, then leaves the skin tight and dry. Your skin will react to this by making more oil, making your skin oil again.
For my skin which is normal, I use 80% jojoba and 20% castor oil. I've been using it for more than a year now. There was a time where my face would get oily during the day but since I've been doing this, I have noticed that I don't have to touch up my makeup ever at work, my lip colour but not foundation, not even on my nose.