I've got level 2 and my oldest villager is a 66 year old woman. Isn't it just a tad strange that the villagers won't breed till the age of 18 but keep breeding into their 50's & 60's?

Can anybody tell me how to get more girl babies born? I've got 16 youngsters (from 2 to 7 or so) and only 4 of them are girls! When they're older I'll have to keep those girls breeding non-stop and that's not fair.

Is there any logic to what gender the babies will be? Do scientists have boys and farmers have girls? Please help before the next generation is condemned to a life of breeding servitude. Thanks.