Re: 2 1/2 month old only nursing every 3-4 hours!!
If her diapers are frequent enough and she's gaining appropriately ... then just feel lucky you got an easy 3rd baby! And remember it'll probably change in a month or a week
However, I might be a little concerned that she's doing a low-level nursing strike of some sort, if she will only nurse when asleep or groggy. Is she a laid-back baby in general? Any other weird behaviors? The good news is this will probably help with your OS/OALD, right? Maybe she'll get more interested when she doesn't have to deal with that?
Nursing, pumping, cloth-diapering, babywearing, working professor mama with the awesomest SAHD ever.