Countess Oona Von Bek, the Dreamthief's Daughter, is the daughter of Elric of Melniboné and Oone the Dreamthief, twin sister to Onric, wife of Ulric Von Bek, and a traveler of the Multiverse.
Una Persson[]
Oonagh von Bek, the adopted granddaughter of Oona and Ulric von Bek, stated:
"I know most of it's true, because I heard the parts I didn't experience myself from Una Persson, as she calls herself now, that mysterious adventuress who spends so much of her time in eastern Europe and never seems to age." -The White Wolf's Son
This suggests that Una Persson may in fact be a disguise of Oona, or more likely, her mother, Oone the dreamthief (since she also looks and acts like her)