Agreed. I switch sides whenever I burp(or attempt to) our son, or when he keeps popping off of one. It seems to work for the most part, but sometimes he follows along the same lines as your daughter, and he'll only feed for half as long as the typical nursing session, take a break while his stomach settles, then cry out for more. And sometimes he doesn't! Sometimes he has watery poops, too, but usually it's the seedy-type. I wouldn't worry! You can't force an infant to feed, so you kinda have to just flow with it. :/ Have you tried burping her when she refuses? That's what I do. Sometimes a burp clears up enough space in their stomach for them to want to eat a bit more. I do that, and if I get nowhere with that, I lay him down in his cradle or rocker or wait it out. He'll either cry out for more a few minutes later, or just go to sleep. But like it's already been said, if she's gaining weight I wouldn't worry!
Oh, I've also read you shouldn't exclusively use one breast to nurse; because the baby can get used to it. Are you switching breasts every feeding, or something? Sometimes it can be difficult - sometimes our baby nurses every 1 1/2 hours, sometimes every hour. It's always changing. Are you sure when she cries, it's always from hunger? 20-30 minutes after a feeding, our baby will cry. But it's not from hunger, it's because he's wet. So I change him, and hold him for a while(he does NOT tolerate being put down after a diaper change, because apparently it's THAT traumatic, lol), and then I put him down, and the next time he cries out, he IS hungry. And the thing is..if I were to hold him, or attempt to nurse him instead of changing him, he'd calm immediately. Him being wet is apparently only a minor concern that's easily comforted by nursing or being held, but if his crying is inconsolable, then I know for a fact he's hungry again.