It's totally normal babyluv But very exhausting I know.
This time of day is often teh witching hour or arsenic hour, only it lasts at least 3-4 hours and babies will generally be fussy and on and off the boob the whole time. It's no reflection on your supply at all. Babies come to the breast for comfort as much as for nutrition, so when they're feeling at all uncomfortable they ask for it, and it's the best way to help them feel better.
This sort of cluster feeding in teh late arvo/early evening can have a really nice side effect - a longer sleep at the beginning of the night.
One thing I would suggest if she is feeding quite frequently during the night is to offer feeds more frequently during the day if if you can. 2 hourly would be quite normal for a babay of this age, and you'd expect 8-12 feeds in a 24 hour peropd (or many more even!).
It sounds like you're doing all the right things, well done!