You can see how Amir is growing as a character. He's slowly transitioning into a "man". “And that right there was the single greatest moment of my twelve years of life, seeing Baba on that roof, proud of me at last.” In the steps of becoming a "man" you become someone your parents are proud of. This quote speaks on a time that Amir achieved this.
I feel like Baba is leaving a legacy of a regular father. Or at least what I look at as a regular father. He reminds me of my dad in someways or other dads that I've witnessed. “And that right there was the single greatest moment of my twelve years of life, seeing Baba on that roof, proud of me at last.” I feel like this quote fits both baba and Amir. This is a special time for Baba because he's proud of his son. Early on in the book you can tell Baba felt like he couldn't relate to his son.
I feel like Soraya and Amir are very similar people. Although you don't completely witness it you still see her grow. This is why I feel like they leave a similar legacy. She's also very family oriented and very caring. “A potbellied man in a deerstalker hat offered three dollars for a five-dollar set of candlesticks and Soraya let him have it. She dropped the money in a little candy box by her feet.” Although this is a small gesture you can tell she's caring. Earlier in the book she also took care of Amir's father.