Neville - an only child?

[amy_marblefeet]

No: HPFGUIDX 73479

Is Neville an only child?

I only started thinking about this after I read OoP again and when 
Mad-Eye shows Harry the picture of everyone in the Order the last 
time around Harry thinks about how similar Neville looks like his 
mother.  A first child nearly always looks more like their father 
than their mother, natures way of a paternity test.  Future children 
are more likely to look like their mother.

So could there be an older sibling out there that Neville doesn't 
know about, or is just keeping quiet about?  It is hard to theorise 
about this as we do not know how old Frank and Alice are at the 
moment to summarise how old a sibling could be.

Just a thought.

Amy