Wow, this is an interesting question and may explain why, though I very much respect the Manning family and sons (what is there not to respect?), I am not real fans of Peyton and Eli.
First, a caveat given for context: I am originally from New Orleans. My family on both sides has roots east of Esplanade. My mom grew up on Franklin and Gentilly Blvd. My dad once lived near Frenchman and St. Claude. I grew up in Gentilly and NO East when it was first developing. Then and now, much family in Metairie (and now in St. Tammany). Those who know how parochial the city is will understand the next comment: When I was growing up, I had limited contact with uptown (except for Saint and Buc games, and basketball games at De La Salle). I certainly knew a lot of kids going to high schools uptown, but I didn't then know anybody going to Newman.
I don't consider Peyton and Eli real, totally authentic, 100 percent Orleanians. I can't totally put my finger on it. Part of it is that the kids are part of the Uptown establishment and went to Newman (see above, and I understand and probably deserve the bashing from Uptowners and Newman grads).
Part of it is that the kids have names like Cooper and Peyton and Eli rather than Buddy or Skippy or Hap.
Part of it is the accent, which may have traces of Uptown but which is just so different from what you hear in the city (we will not hear Peyton tell the female sideline reporter after the game: "Darlin', when I threw that pass, I just said, 'Oh my Gawd!'").
Part of it is the college choices and the feeling that LSU was never a serious option for the boys. Cooper and Eli went to Ole Miss, a decision totally understandable given that mother and father attended Ole Miss (and a popular choice of Uptown kids). But Peyton's Tennessee choice--not LSU, not even Ole Miss, but another SEC school--rankles still.
In summary, the Manning kids, especially Peyton, are from New Orleans but in terms of culture are not totally part of New Orleans. Indeed, in terms of culture, they probably are a tad more from Mississippi--in speech, in manner, in outlook--than from New Orleans. And the reason is Archie and Olivia are from Mississippi, and the family's roots are there.
Let me quickly add that this is not a criticism of the family. Archie and Olivia seem very committed to the city and have contributed greatly to many worthy causes over the decades. They have obviously done a super job of raising children who seem like high quality human beings. And I will probably be pulling for Peyton tomorrow--though not as much as my mother who is a huge Peyton fan.