Vivienne - that's great, so glad to hear that your poor nipples have recovered and that you are breastfeeding well. It's just the initial stage that's so teeth-gritting, isn't it? Once the nursing routine is established (for me, it was around the 4 week mark), then bubs can latch any which way and it doesn't seem to hurt. (Mine also has this naughty habit of twisting his head with nipple in mouth when he's almost done so it's stretched like elastic! And even though it looks nasty, even that doesn't hurt!!)
Cxflygirl - I don't think everyone needs to nurse for 30 mins. It depends on how fast your let-down is and how fast your milk flows, and of course how fast your baby can drink. With mine, he's quite a fast feeder and can drain my breast in about 10 mins. (I try to keep him at it for 15 mins if possible at each feed.) I'm told I have a quick letdown as it only takes me 10 mins to drain a breast while pumping (I can pump about 100 ml from one breast when it's full/engorged.)
I think the important thing is that your baby looks fulfilled after nursing - and of course, that she is gaining weight steadily.