The Charmed Seastar (Fem! Percy Jackson and charmed 1998 crossover.)

After the war against Gaia, Persephone Jackson goes home to find her mom sally dead of Cancer with a single note addressed to her written by sally in her final days.
But the note Reveals that sally was never persephone's true mother in fact she is the youngest daughter of Patricia Halliwell and that she herself is a demigod and a witch.
So she goes back to camp to tell her boyfriend andrew only to find him in the middle a make out session with Drew Tanaka, in angry, scornful tears she breaks up with after drew reveals they've been going behind their backs for a full year, So she grabs her best friend's and cousin's Jaesa, Nico, Leo, Thalia, Hazel, Piper and Frank and moves with them into a nice suburban neighborhood in San Francisco with help from the gods, she meets her two older sisters, Piper and Phoebe Halliwell who she moves in with to reunite the power of 3, thankfully she lives only a few miles away from her cousins.
Piper and Phoebe Are just having the worst week of their lives as they've just lost their beloved sister Prue Halliwell and with the pwer of 3 broken they struggle to get past it, but that's when their mother shows up to give them some news and much needed Relief as Patricia Reveals to them A secret little sister that she had with the god of the Sea, Poseidon himself, however she warns them that Persephone is and always will be hunted by monsters almost nobody else can see and gives them both the basic gist of the 2 wars but also informs them that in addition ti persephone's powers she gets as a demigod, she also inherited All the same powers as Prue and tells them that she lives with friends and cousins in a neighborhood 2 miles from the P overlooking the harbor and tells them to convince her to move into the house and reunite the power of 3.

Obviously I don't own charmed or the HOO so credit goes to Rick Riordan and the Creators of Charmed (1998) go check both out, treat yourself an enjoy.