It may take her a while to adjust but you could try exposing her to some sunlight everyday. Try to keep the house bright during the day and allow it to be a bit noisy. Not loud and chaotic but expose her to normal, day-to-day sounds. Then, at night, keep the house as dark and quiet as possible. Minimise noise, dim lights, use a small night light for nappy changes etc.
It's a stage that lots of babies seem to go through, maybe partly because feeding between 1am and 5am is the best time to maximise milk production (it is when prolactin levels are highest). Until she resets her body clock make sure you get plenty of rest during the day with her. And congratulations on your new little one :-)