Posted:
hehe..when I said first cousins, i meant cousins once removed..
but Molly & Draco are cousins by marrige! Its Molly-Siruis-Bellatrix-Draco!(fill in the missing people that they havent mentioned in the books too many times)
so they are related by lots & lots of marriges..
It could be possible. I didn't say they wouldn't be.
Recall
"Chances are though that they are cousins of some sort seeing as pureblood wizarding families do tend to inbreed."
Them related to eachother by marriage isn't exactly a big deal as they're not blood related. Molly is blood related to Ignatius Prewett while Sirius is blood related to Lucretia. Molly and Sirius, however, are not blood related to eachother simply because they're cousins by marriage due to Ignatius and Lucretia. Sirius and Narcissa are first cousins and Draco and Sirius are first cousins once removed so Sirius is blood related to Draco who is (once connected) is not blood related to Molly. If the connection were to be made simply because of this then a romance between any of the Weasley children (Bill, Charlie, Percy, Fred, George, Ron, Ginny) and Draco is entirely possible and they can have children together as (well Ginny and Draco🤢 as some may not be too interested in Mpreg) their DNA is not closely matched. Inbreeding occurs when one marries or breeds with those who are first, second, third...cousins (even if once, twice, three times...removed). The closer the number, the closer their DNA. Inbreeding does not occur in cousins through marriage seeing as they don't have common ancestors (or have one that is way far back in the tree).
As the example of Sirius's parents (along with the Gaunts and Sirius's comment regarding this) indicate, however, is that inbreeding is fairly common in pureblood wizarding families so Molly and Draco could very well be distant blood cousins. If we're only using "cousins by marriage" thing then they're not blood related, at least not by anything I've read in the books.
Generally speaking, in the real world, people tend to avoid breeding with their closer cousins and many countries have laws restricting first cousins but I think some consider it fairly safe to breed with their second cousins, third cousins, so on and so forth.
