The Prince and Filch Family Trees

[abergoat]

No: HPFGUIDX 156637

Abergoat speculates:
Potioncat (whether she wants to take credit or not) helped me cleanup
a few outstanding questions about first year Snape's knowledge of more
hexes than most seventh years and the weird timing of Snape 'running'
with Belletrix Lestrange even though she was born in 1951 and he
wasn't born until around 1960 - seemingly eight years or nine years
later. And I think it ties to the Filch and Prince family trees, along
with Voldemort's acquisition of the Ravenclaw relic. I believe Snape
was raised at Hogwarts by his distant relations - brother and sister:
Argus Filch and Irma (Filch) Pince because Voldemort had killed
Severus Snape's parents to acquire the Ravenclaw relic.

Many people will think this is too complicated - but I remind you JKR
has said she intends to tie the story up into a big knot. And we now
SEEM to have JKR's word that Snape is working for Dumbledore's side
and Dumbledore certainly trusted him 'completely'.  To me that
suggests a family connection that causes Snape to hate Voldemort.

So hear we go:

The Family Trees

? and ? Prince give birth to son (Eileen's father) and Agnes (dog lady
at St Mungo's)

Son Prince marries ?, the heiress of the Ravenclaw relic and they have
a daughter Eileen. Eileen's mother dies early. The relic passes to
Eileen. Agnes stands in as a mother to her young niece as much as she can.

Agnes Prince marries a Mr Filch and they give birth to son Argus and
daughter Irma. Mr Filch is an abusive man and becomes particularly
abusive when his son proves to be a squib (this is possibly the memory
Harry saw...it may have been legilimens Snape's memory OF dog lady's
memory...not Snape's own childhood)

The Relationships

Agnes (now dog lady of St Mungo's) was aunt and surrogate mother to
Eileen (Prince) Snape. She is the Great Aunt of Severus. Squib Argus
Filch of Hogwarts fame and his magical sister Irma are Eileen's
cousins and therefore distantly related to Severus.

Voldemort's Interference

I speculate that when Voldemort came for Eileen's relic (assuming she
had the Ravenclaw relic) he found Agnes Filch and her abusive husband
in residence. Eileen had called in her surrogate mother to help with
her new baby Severus. Voldemort killed Tobias and Eileen and setup Mr.
Filch to take the blame for the murders - he left the baby alone
(hence Lily's belief Voldemort wouldn't hurt Harry). I suspect that
Agnes may be one of the seven registered animagii of the last century.
 Voldemort left her halfway transformed, again with Mr Filch, Argus
Filch's father and Agnes's husband, taking the blame.  Or perhaps
better yet, the trauma of the scene is thought to have caused Agnes to
'make a mistake' leaving her in a state where she can only bark.

Final Consequences

This pretty much decimated Severus's family. The ones that aren't dead
or transformed are outcasts. No one wanted anything to do with Irma
and Argus because their father was thought to be a murderer.
Dumbledore, who knew Eileen because of her defense of Hagrid in the
first CoS opening, hires them. Perhaps Mr. Pince didn't die, but ran
off when his wife seemed to be the daughter of a murderer. But who
brings up Severus then? Does he know more hexes than most seventh
years because he was brought up at Hogwarts by Irma and Argus?

I do find it interesting that we never see Irma Pince and Severus
Snape interacting. Although we do see Filch playing the surrogate
father binding Snape's leg in PS/SS. 

So the 'son' that the nurse at St. Mungo's says is coming to visit
Agnes would be Argus Filch. And my idea that Severus Snape learned
healing to try to heal Agnes is still accurate, he wanted to heal the
mother of his surrogate parents, Argus and Irma. And Snape hates the
world for treating them the as outcasts. And perhaps Lily helped
Severus with his efforts to heal Agnes, and Lily was perceptive enough
to see that Agnes was trying to tell them something...so Snape learned
legilimens. This would have Snape learning via legilimens that
Voldemort was the one that killed his parents and ruined the lives of
his surrogate parents by pinning the blame on their father.

Wild? I don't know...it is supported by a number of canon tidbits. As
I mentioned earlier it explains how Snape 'ran' with Belletrix
Lestrange even though Bella was at least seven years older than
Severus...Severus was at Hogwarts the entire time she went to school
there. JKR is sticking our nose in the fact that Bella is
significantly older than Snape - so old that one would think they
didn't overlap. And this may be why Severus Snape chose Slytherin
rather than his mother's house - Ravenclaw. Because Bella talked him
into it.

As an added bonus it explains why James hated Severus Snape on first
sight as canon tells us - Bella liked Severus and Sirius hated Bella.
That would probably be enough for James. 

Just having fun speculating.

Abergoat