Awwww, look at his freckles and her beautiful, big, dark eyes. You have captured them very well. Nicely painted. I am sure that his son was ecstatic!
Doing a head and shouldres pair together can be tough compositionally. Want a little composition tip I have picked up along the way. If one or both subjects are at an angle place him/her so the head/shoulders face inward. It not only helps to keep the viewer within the confines of the portrait but makes the subjects seem more related to one another. Layout designers do this all the time. They will even reverse a picture so that it faces inward for an ad or magazine article. That's why sometimes you might catch a picture with backward writing in these.
In portraiture, there are exceptions of course - like when you want a subject with a way off in his own thoughts look. Another one is if you are wanting to make a statement about a relationship such as a parent/child grouping where your trying to capture an 'independence' portrayal for the child.