My condolences to your friend and the loss. It never gets easy, it matters not how many close to you, you lose, they all touch you. I can not imagine what it is like to lose a child. Sometimes the words will not come, like you said, but there are times the grief needs to be shared, and the person just needs someone there with them. It sounds like that is what you did for your friend. The grammar the punctuation, the flow of words of a post are meaningless, I think we all got the message despite any of that.
His daughter sounds like she was a very fine young woman.
This is all anyone can do IMO. There are no words that fix something this devastating.