Here's another great reference chart from Joumana Medlej, majnouna.com. The "Artists Guide to Aging Characters" was created for those drawing human anatomy but it is also useful information for those sculpting figures and creating dolls, especially for the facial features. It shows the changes in proportion and other changes that happen as a person ages from a baby to a senior citizen. See more charts at majnouna.com
Note: The actual size of the image is a lot larger than the way it displays in Blogger. Chart is much easier to read if you download a copy.