Mother cat giving birth

Question
I have a feral cat that my mother took in. She became pregnant some time ago. Today she gave birth to her first kitten approximately 4-5 hours ago. Since then, theres been no more kittens even though it's obvious that there are other kittens inside her.
I've also just noticed a red sac hanging out of her vagina. I don't see a head or anything so I don't know if this is the placenta or another kitten that she cannot squeeze out for some reason. At the time she is nursing the one kitten and drinking a little water.
My question is are the kittens and the mother in danger since it has been so long in between births?

Answer
Hi Valerie.  I guess this question was asked about 11 hours ago, so maybe she has resumed delivery.  If not, then it would be wise to consult a vet.  Also, the red sac does concern me.  If you didn't count a placenta for the kitten that she already delivered, then it could be the placenta for this baby as they sometimes become detached during delivery, so that would be okay.  But if you have already counted a placenta for the first born, it might be a placenta that has become detached from an undelivered baby or a baby stuck in the birth canal, and that little one is in serious danger, as is the mama.  The red sac could be a kitten on the verge of delivery, but the amniotic sac is usually more like a gray bubble in appearance.

Most deliveries are finished within the space of a few hours.  On average, a kitten will be delivered every 15 to 45 minutes until the entire litter has been delivered.  However, it isn't extremely uncommon for there to be longer breaks in between with some cats.  A cat's uterus is divided into two horns, and most often, the kittens from one side will be delivered before the kittens from the other side are.  Sometimes there may be several hours between the deliveries, and as long as she isn't having contractions, it's not a concern to wait even as long as 12 hours.  

The most dangerous sign is when a mother is straining to deliver for more than 45 minutes but is unable to do so.  This would certainly be time to get the cat to the vet.