I think it would probably been quite comical, a good looking female (hopefully) with Data's traits. Lal made a great daughter (excellent episode) but I don't think that this showed how a female Data would be. Since reading this thread I hhave tried to imagine it and it doesn't work for me. Perhaps I too used to seeing Data as introduced in episode 1 of TNG. This would also have meant that she would have had a psycho sister (or two), now that would have made an interesting script in 'Brothers' obviously renamed 'Sisters'!