If they are heading for the hut it is too late, she could have the baby anyway. If you don't want one particular woman going off to get pregnant without your guidance, I suggest you set her skills on something other than parenting. If she's really into farming, she won't be as likely to go off with some guy towards the hut.

First Peek alternates which members get to try a beta. You will get an email inviting you to beta the game and submit a form with your results. You will often find that people in the forums are indicating that they have received a First Peek email. Do not be alarmed if you did not, as playfirst rotates the betas to give everyone a chance.