My baby was born at 28 weeks and 1 day?

My baby was born 12 weeks premature and she was only 1 lb and 11.5 oz. I'd had pre-eclampsia, I'm guessing for a little while but the doctor just said it was my nerve. I finally got diagnosed when it got severe and I had to deliver. She was healthy, active and alert. She is about 10 days old now and they have her ventilator lowered from what it had been originally, she's being fed and she's almost 2lbs now. (2.5 ozs away). She's gaining a bit and breathing more on her own, active even in her sleep and she's got pretty quick reflexes. What I'm asking, is does it sound like she has a chance? The nurses keep saying she's doing good and great but yesterday she lost 1.5 ozs and as a precaution they had to raise her ventilator. Do any preemies go through ups and downs or just the ones who are too weak to live? I can't stop stressing out and it's scaring me so bad. I know people who were born worse off and who were born at the same time she was, but they never said they had ups and downs. If anyone could give me any sites I could go to and read about premature baby development that would be appreciated.