My theory is that Muhammad, a famous womanizer, got her pregnant, had to get her out of town. But never married her, because the relationship ended right after UBL was born and UBL's mother was so scorned by Muhammad's other wives.
The custom was to have all the wives living together, but she moved out of the harem 6 months after UBL was born and raised UBL outside of the harem until he was about 7. Very odd for any male child to be taken out of the father's house.
