And that maturity (if true) is, imo, a miracle which borders to implausibility.
17-yo guys were in those days not usually mature enough to be at the emotional level ready for fatherhood. It caused tensions. Please read how it was with king Louis XV of France and his eldest son, the dauphin.
In my opinion, George is still emotionally fairly boyish, and 'on prowl'. He would imo feel somewhat caught, were he to settle to take care of a kid or kids. However, fortunately for this, he will be a lot absent, being in ship. His visits to 'home' would probably feel just good to him, because that home is not tying him down. He would, in my prediction, behave a lot like a young uncle to his kids. Life would be playing and gaming with his kids, not the grave business of taking care as settled father. That, of course, puts his wife to the unenviable position of 'single' caregiver, the parent who IS present. By the way, the peripathetic lives of many husbands in earlier centuries - as well as polygyny (several wives each in separate hut with kids birthed by her) another custom of earlier centuries in many places - were things which made the father's role approximately as like this.
Of course, if you mean by 'make great father' that he will behave like a young uncle towards his kids, then....