She could be William’s son by a previous marriage.
1850 Gallia Co., OH census (Ancestry.com): Henry Crease (sic) (82 VA) living in Perry twnsp with: Delia Crease (42 VA); Mary Crease (22 OH); George H. Crease (20 OH); Absalum Hughs (5 OH) and Madalane Hughs (3 OH). (SV-284)
How is she related to John Hughes (ID no. 11095) ??