Harry and Neville: Brothers?

[justcarol67]

No: HPFGUIDX 86834

Derek:
Okay, a bizarre thought just hit me.  With all the emphasis on
twins in the HP books, and with both Harry and Neville born on
the same day, is there any chance they are twins, and that fact
is being hidden from them?
 
I've no canon to support this, of course, but it would certainly
be an interesting twist...
 
Serena: 
It doesn't say they were born on the same day in canon, only they 
were both born towards the end of July.

Carol: 
Also Harry closely resembles his father but has his mother's eyes,
whereas Neville resembles his mother (even Lucius Malfoy, who's never
met him, is able to identify him on the spot because of that
resemblance). BTW, I haven't noticed any emphasis on twins other than
Fred and George, but we do have pairs of contrasting brothers or
sisters (Sirius and Regulus, Lily and Petunia), etc. I think that
Neville, like Young Tom Riddle, functions to some degree as a foil to
Harry: a character in a similar situation who reacts differently. The
three could even be considered as a sort of triangle--the boy who went
wrong, the boy he turned into his rival, and the boy who could have
been that rival but wasn't "chosen." All three are effectively, if not
actually orphaned at an early age, all three have someone on whom they
could seek revenge for their situation, all three are or will almost
certainly become powerful wizards, but all three react differently to
these circumstances. There's no need for literal brotherhood or blood
relationships here. The parallels and the contrasts are what matter.

Carol