I have to say I am experiencing this from the opposite direction. Before HRT and dieting my face was seriously round and fat. It has taken ages for the fat to go from my face. There is still puffiness from excess skin and some residual fat in my jowls. My relatives used to tease me and tell me I had a big round ball for a head

Given enough time the body will do what it needs to ensure the correct amount of sub-cutaneous fat is evenly distributed according to your overall body weight. Failing that, as other have already mentioned albeit a bit extreme IMHO, there's always fillers to plump them up.
I think CarrieLiz said in another thread that overall 10% new fat cells can grow in a year, so maybe if the conditions are right then some may grow naturally in your cheeks too.