So long as there are no weight gain concerns and you haven't been advised to feed more regularly, then I would go with it. If she's well, she knows when she's hungry and will let you know.
Mine had a lot of weight gain issues in the first month (it took her 26 days to regain her birth weight after an initial loss) and we were advised to not go longer than 3 hours between feeds, so we did wake to feed. If you haven't been advised to do this though, I would go with it. By 5-6 weeks, our feeds were still every 3-4 hours (I was BF then) and usually 2-3 times during the night, but she was waking up hungry. If she's fine, I would just trust her and go with it and get yourself some extra sleep while you can.