Ok, first thoughts...
Are you noticing anything in particular during the feedings that you might say was causing her problems?
I assume she's growing well and doesn't appear dehyradted.
Have you been writing down (keeping a log) of when she eats, is awake, and sleeps? If you have, do you see a pattern at all to her feeding? If you haven't, I highly recommend writing these things down. It will really help you whenever you encounter problems. Is she feeding every one to two hours around the clock, or does she have at least one time when she goes for a longer stretch between feeds? Is she more often going two hours, but sometimes going only one hour between feeds? Is this a new habit for her, maybe caused by a growth spurt, or has this been happening for quite some time?
Be sure to count 'time between feedings' from the beginning of the first feed - not from the end of the feed. For instance, if you start breastfeeding at 8:00am and she feeds for 15 minutes and then she wants to feed again at 10:00am, that is going 2 hours between feeds, not 1 hour and 45 minutes.
I wouldn't say she's not getting any hindmilk. I believe the hindmilk comes in after about five minutes of feeding. However, she is obviously not getting enough milk overall to hold her over for 2 1/2 to 3 hours. If you're single side feeding then I'm sure she's getting some hindmilk. By the way, is she a small baby? Smaller babies have smaller stomachs and need to feed more frequently until they're larger.
Please don't panic about her not going exactly three hours between feeds, even at eleven weeks. '3 hour EASY' is only a guideline...remember to listen to your baby first! If, at eleven weeks old, she is consistently awake after feeds, then sleeping, and eating again after she awakes, you have come a long way and are on the right road. However, having said that, and assuming there aren't really any other problems for you or the baby, you can help your daughter adjust to a more practical timetable. Here's my recommendation, but remember it's just that. Others may feel differently. If you know her basic routine, you can slowly help her go for longer stretches between feeds. SLOWLY. Have her wait just 15 more minutes before eating. She should be hungrier and hopefully take a bit more in. After several days to a week of this, extend her time between feeds another fifteen minutes. Over several weeks, her tummy and your milk supply should both adjust to 2 1/2 to 3 hours between feeds. Remember that sometimes she will still want to go for shorter times and remember that she will hit growth spurts. This is where listening to your baby and keeping a log come in very helpful.
