Does the skin look dry?you can try to apply virgin coconut oil after her bath time. VCO also has anti inflammatory and antibacterial properties. However, you have to do patch test first,in case your baby shows allergic reaction to VCO even though it is a natural remedy. This is a good article for your reference: http://www.bellybelly.com.au/baby/coconut-oil-5-great-uses-for-coconut-oil-for-your-baby/
Our baby had infant acne as well on her cheeks. We applied extra virgin coconut oil after her shower and now it's mostly gone. She's about 11 weeks now. You can see her pic from last night. Check out this article for more on infant acne. It's really good. http://sg.theasianparent.com/what-you-need-to-know-about-baby-acne/