You have not mentioned about how prematurely the baby was born. Duration of stay usually depends on degree of prematurity. Most often they would be in the nursery till they have attained a maturity of 34 - 35 weeks and are taking direct feeds, gaining weight and maintaining normal temperature outside the incubator. I think the baby may need to be in the nursery for another couple of weeks. Some premature infants are at higher risk of infections later on and slow development. However, many of them grow normally. You just have to monitor her physical and neurodevelopmental growth over a period of time.