I know it's hard, but try not to focus on the milestones too hard. Every baby will develop differently and at different times, no matter when they were born in their gestational cycle. But if you are looking for a straight answer, then measure her milestones by the gestational age, so her age now minus 5 weeks.
I have a 9-month old son who was born 7 weeks early. We just had the 9-month check-up and when the doctor started asking developmental questions I had to answer "no" to a lot of them. It's a little disheartening, but she said, "Don't worry, he's a preemie." He's such a robust little guy, it's easy to expect him to be doing all the 9-month stuff, but the fact is he'll always be just a little behind. Keep in close contact with your doctor so that she can tell you if you need to worry. Other than that, enjoy your baby!