As far as I'm aware, the plug is there to prevent anything getting into the womb during the pregnancy and possibly damaging the sac of amniotic fluid or harming the baby.

For some women (rare cases - first timers) the time between breaking water and finish can be as long as three to four days, sometimes longer. But that is extream. For first time labour, the time is rarely less than six hours.

The second child, labour can be as short as one hour.

Extream short time (I am not sure if this was the woman`s fourth or fifth child), she brock water while shopping, drove to the hospital and the child was already halfway birthed by the time she got to the emergency ward.

There are absolutly no averages.

One thing to factor in is body shape. There was a reason why men wanted their women to have wide hips (child bearing hips). It was so that the woman in question would have an easier time having children and the less possibility of her death. Now with C-sections, that is largely taken out. Women with narrow hips can have a 10 to 13 pound baby, which in earlier times would have almost guranteed her death.

These are things you have to think about with your character.

Hope this helps. You can say almost anything, as long as it isn`t too outlandish.

Leto