double-Black / Sirius & Slug / Half-brothers / Prophecy

[Catlady (Rita Prince Winston)]

Talisman wrote in
http://groups.yahoo.com/group/the_old_crowd/message/3911 :

<< > http://www.the-leaky-cauldron.org/#gallery:pic:8644
Interesting how Sirius and Regulus are *doubly* Black. >>

I've always said that Mrs Black's phrase 'the house of my fathers' was
neither erroneous nor evidence that the house hadn't been in the Black
family long. Except I thought Mrs Black and Mr Black were probably
first cousins, and on this chart they're, what, second cousins?

Olivier wrote in
http://groups.yahoo.com/group/the_old_crowd/message/3929 :

<<  Especially since it is also strongly suggested that Sirius was
invited to Slughorn's parties too >>

I suppose both Sirius and James were invited to the Slug Club --
bright, wealthy, popular students they were -- but I have trouble
imagining Sirius wanting to return after his first visit. He may 
have liked being fawned over by Slughorn more than Harry did, but 
he wouldn't have liked associating with Dark or nerdy invitees.

Randy wrote in http://groups.yahoo.com/group/the_old_crowd/message/3933 :

<<  Did someone suggest that Snape and Sirius were half brothers (ie.
half a Black makes you a half-blood prince?) >>

I suggested that pureblood Eileen Prince married Muggle Tobias 
Snape because she was pregnant by married Mr Black (and the Muggle 
was the first man her Love Potion worked on -- I imagine wizards 
have antidotes). But I don't think JKR would put that in her story.

Dungrollin wrote in
http://groups.yahoo.com/group/the_old_crowd/message/3935 :

<< "If Voldemort had never heard of the prophecy, would it have been
fulfilled? Would it have meant anything? Of course not! Do you think
every prophecy in the Hall of Prophecy has been fulfilled?" >>

If they don't expect them to be fulfilled, why do they file them in
the Ministry of Magic? I don't understand why the wizarding folk make
a BFD about prophecies if they know that prophecies are a pile of trash.