Re: Issues...plain and simple
Congrats on the new baby! If your baby has already shot up to 10 lbs at 2 months old, you must have the fundamentals of breastfeeding right, and tweaking the fine points is a lot easier than fixing the fundamentals.
I would be surprised if you had low supply in the wee hours of the night. Most women notice that their supply is more abundant in the night, not less, because prolactin levels generally peak in the night and then decline throughout the day. Can you describe the behavior that's making you feel like there's no milk? And can you tell us if you're taking any hormonal contraception?
If you want to increase supply at a particular time of day, the key is to remove more milk, more frequently at that time. The increased demand will trigger increased supply. You could accomplish this by nursing more, or by pumping in addition to nursing. A cup of fenugreek tea before bed probably wouldn't hurt, either.
It sounds like your baby also has a fussy time in the afternoon/evening, right? If so, it's very normal, and the best thing you can do is... You guessed it: nurse, nurse, nurse. Just go with the flow and she will grow out of it.
Regarding poop- as babies grow their digestive systems mature and they start using breastmilk very completely, with little waste left over. When this happens- and it happens at a different time for every baby- poop frequency slows down a lot. As long as your baby continues to gain weight and the poop is soft when passed, it's okay for her to go up to a week with no bowel movement.
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"