But, hey, I must admit I never made it through tohse books of all the begats -- but I did get the distinct impression, the ancient Hebroos (or at least, their chroniclers) were more into fathers and sons, with women seen basically as only a necessary tool on the way.
So, are youy sure it actually says what became of old Oldy's _daughter(s?)_? Maybe she wandered off out of the book -- towards the northwest and discovered Europe, or something. [Edit: Add main point, dickhead!] And maybe she left at a very young age, and learnt the (non-Hebrew) language of the tribes around her, I mean.