If reflux, she'd be more likely to feed very frequently and would be pretty unsettled too.

IT is quite normal for brand new babies to spend a lot of time at the breast, but soe babies are quicker. Just luck of the draw. They all get quicker in time (relatively speaking). Then sometimes they want to spend more time there and sometimes they just want a quick feed adn they're off again.

It does sound like you have an oversupply. Do you block feed at all? (keep feeding from same side till it's empty) If you follow her lead and let her feed as and when she wants then your supply situation should sort itself out. It is still quite early days forthe both of you.
Anyway sounds like she's doing very well.