It wasn't an uncommon occurrence for Faramir to muse about the past. Even now as he was holding his son for the very first time, he couldn't help reconsidering the events that had allowed the creation of such a precious thing.
If his father hadn't sent him back to Osgiliath then he wouldn't have probably come so close to death; however, that also meant he wouldn't have got the chance to meet the woman that was now his wife and the mother of his child. And Éowyn wouldn't have been in the Houses of Healing at all if her unrequited love for the Lord Aragorn hadn't prompted her to seek a brave death in battle.
The hand of the King had saved them both, and yet even Aragon wouldn't have been able to do anything for them if it hadn't been for Faramir's kinsman.
Prince Imrhail had ridden to his nephew's aid and borne him away from the battlefield; he'd also been the one who noticed that Éowyn was still alive and ordered her to be taken to the Houses of Healing.
Faramir owed his present happiness mostly to his uncle, and he wouldn't forget it until his dying day.