Turmoil on the Thames — Marissa Doyle

Young widow Annabel Chalfont, Countess of Fellbridge, has two small sons to raise, a mountain of her late husband's debts to pay off, and a secret: she's a shadow-shaper, able to manipulate shadow as anyone else might clay. She and six other high-born ladies with equally extraordinary abilities defend England against supernatural crime—but the world knows them only as the Lady Patronesses of Almack's, Regency London's most exclusive social venue. Annabel is off to Eton to visit her sons for the annual celebration of the King's birthday, observed with a picnic and boat race on the Thames--neither of which happen in quite the way they should. Thanks to Annabel and the Marquis of Quinceton, tragedy is averted, but the Ladies of Almack's are worried about what happened on the river, and what else might occur...