Cousins by marriage ?

[scoutmom21113]

No: HPFGUIDX 106493

Eris wrote:
(although I'm not too clear on how this 'once removed' business 
works).

Bookworm:
As I understand the genealogy, Sirius and Andromeda are from the 
same generation, and are first cousins – they share the same 
grandparents. As Andromeda's daughter, Tonks is Sirius' first cousin 
once removed.  I think of it as straight lines between cousins in 
the same generation (first, second, etc.), and diagonal lines to 
the "removed" relatives who come from different generations. 

It gets really confusing when there are wide differences in age. My 
second cousin once removed is my age. Her grandmother was my 
mother's first cousin, so her father was my second cousin. 

Del replies:
I disagree. The way Sirius said it, just after explaining that all 
the pureblood families are inter-related and that this means that 
the choice of partner is very limited if your kids are to be pure-
bloods too, I take it to mean that *both* Molly and Arthur are blood 
relatives to Sirius.

Bookworm:
In theory, Molly and Sirius could be "cousins by marriage" if 
Molly's cousin married Sirius' cousin. There would be no blood 
relation between Molly and Sirius.  In practice, however, you may be 
right.  

This could be an area JKR didn't think about in detail when she made 
them cousins by marriage, but said someplace else that all the 
families are related.  Or it may be the relationship is so far up 
the family tree that it hardly matters.  (Do you think we will ever 
fint out?)

Ravenclaw Bookworm