she was 45yr 6m at conception 46yr 3m at birth - ok guess about possible though quoted fecundity rates for age cohort 45-50 is about 18 children/1000 woman years and drops very quickly with age (see discussion in English Population history from Family Reconstitution by Wrigley et al) - if you want a modern example of the Moses phenomenon try Hall Caine - his son's illeg daughter with a married woman was passed off as his own dau his wife going along with it