Sorting Hat and Gryffindor Weasleys

[annieclaire12 at yahoo.com]

No: HPFGUIDX 28641

The sorting hat has fascinated me from the start.  In PS it seemed so 
arbitrary, even when viewing it from Harry's POV.  Through the 
archives I read some excellent posts which have provided me with 
added depth to the sorting process.  But I have a couple of questions 
about the sorting hat with regards to the Weasleys.

With reference to sorting hat process, in post 23442 dfrankiswork@ 
wrote:  
>characteristics (I am brave), aspirations (I want to be brave), 
>priorities (I think bravery is the most important thing), morality   
>(bravery is good) and choice (I want to be with the brave)

Also regarding the sorting process, in post 23468 caliburncy@ wrote:
>I believe (with no evidence from canon) that the Sorting Hat makes 
>it decisions based largely on another option: potential for growth


Both of these terrific posts helped to clarify for me the sorting 
process as it stands now, pending any further illumination from JKR.  
Based on what I've gleaned from these examples, the hat considers a 
number of factors (aspirations, personal choice, potential for 
growth) inherent within each student.  Although the factors are 
unique to that individual, as a whole they predispose them to a 
particular house.  Neville and Hermione may have different traits and 
varied priorities, yet in the aggregate they each reflect the 
Gryffindor spirit.

My question is with the sorting process and the Weasley family. To me 
it seems a little odd that every member of a large family such as the 
Weasleys would each be a Gryffindor.  Surely in a family of nine 
there'd be some sibling that is in total opposite to another in terms 
of house predispositon.  So in addition to the above factors, does 
the sorting house also consider family history?  Like a 'legacy'.  
While JKR did separate the Patil twins, she also kept Draco a 
Slytherin.  

So I guess my question is, how much of a factor do you think family 
history is to the sorting process?

Annie-Claire (whose only other example of a 'legacy' is Flounder in 
Animal House)