my guinea pig is pergent. i think?

Question
   hi my name is megan i have this problem i have a guinea pig and so does my sister, but at frist we thought they were both girls till the other day when my guineas pig started getting fat in the butt.i notice it getting bigger and bigger then when i touched it i felt something move and so did my mom. i was wonder how? but then found out my sisters guinea pig is a boy.but also my guinea pig is 3 years old. is it true that if she is pregnant she will die and so will the babies. and is there anyway to save any of their little lives. :*(  

Answer
I am going to be honest with you. There are very high death rates with guinea pigs giving birth. The female could die during the birthing process because the babies are quite large when they are born. They are born fully furred, eyes open and ready to run. You will need to make sure that the mother is comfortable and watch the birthing process. Guinea pigs stay pregnant for about two months. Here is a website that contains information on the reproduction of guinea pigs as well as when to seperate them. http://www.guinealynx.info/reproduction.html