Babysitting with pregnant cat

So I'm babysitting for my aunt and uncle who have three kids. They have three cats and four dogs (including a puppy). So one of their munchkin cats is like reallyyyyy pregnant and I'm just hoping that she doesn't go into labor while I'm here. I babysit from 7:45(ish) till 5. Is it normal for the cat to randomly smell really bad? I know I sound stupid but she sits next to me and suddenly it's smells so bad that I almost puke. But if she does go into labor while I'm here any advice?