I started out writing about the family curse for a lore post. It ballooned into a full short story or scene where Ally meets her betrothed's deity and learns some of the family history. His deity turned out to be friends with the deity of the O'Drakes, who used to be very close with Mara and her sister.
This is set in the future. Ally and Kirsty are in their last year of school. Things have not come to a head with Astereth just yet in either Selkies' Skins, Dragon Shaman, or The Shadow Chronicles just yet... However that's just around the bend for all three slices of the world or worlds.
With this in mind you can read about The Harper Family Curse: Shadow and Fire.
Be warned. Before this only one other person knew what was in store for Kirsty and David, and Thomas and Ally.