In the early stages Ash would feed anywhere from 10 minutes to 45 minutes on one side, then burp and top up on the other side. The top up side was usually 5-15 minutes and he would fall asleep feeding. I would burp him again and put him down or in the sling or whatever. The next feed I gave the same boob that he has topped up on so this one got emptied properly and the top up was the other one. That way they are rotating
Now he is on and off in 10 minutes tops Once she gets more efficient at feeding you will find you wont feel like you are feeding constantly... until they go through a growth spurt and that is a whole OTHER fun time lol

Oh and also remember she is trying to built up your supply to her needs. It really is early days. Take it easy, offer the breast when she wants it, and rest while she's feeding.