That makes sense! I was reading incorrectly that you were either pumping or feeding every 4 hours all day/night. I would actually say that what you're experiencing is normal. There's a huge range among women for how long it may take a supply to regulate, so there's not really a "too early" or "too late".
When she'd done feeding at night, is it that she's fallen back asleep or that she removes herself from the breast awake? If she's awake, I would offer the other breast. If she's asleep, I would let a sleeping baby lie. Has she gained enough weight that she's reached her birth weight again?
There are a lot of hurdles when breastfeeding that will make a woman wonder about her supply. The best way to tell if a baby is getting enough breast milk is by counting their wet diapers. By about a week old, they should be having 4-6 very wet diapers each day. So if you ever start to question or wonder or some crazy nurse advises you that your supply is suffering, just count those diapers.
There's a fantastic site: kellymom.com that's full of reliable, evidence-based breastfeeding information and it's all very well organized. It's the go-to resource for a ton of us.
Feeding on demand is really all you need to do-- it sounds like you're doing great! Just keep up the good work, the pain will be gone before you know it, and it'll be smooth sailing.