I have found something very interesting for myself when making portraits of family and loved ones. It comes from all the times I have looked at old pictures and thought or asked "when was this from?" or "Yikes, how old was I here?"
I state the age as the title of the pictures. "Chuck at 40". "Maddy at 12". It's weird, and maybe only for me, but the title actually adds something to the photograph. It's like the age kind of reverberates around in your head at the same time that you are looking at the person's expression, features, and eyes.
Just a thought.