Zarava, she feeds several times a day lol though they're usually shorter feeds. She tends to have periods of being on and off the boob with little sleeps in between, and then have long sleeps before the night wakefulness. Good point about the lighting, I've found that I've been sitting in the living room with the overhead light on because I don't actually own any lamps! Perhaps that would be a good investment!
If she's falling asleep on the boob after a couple of minutes i would suggest to wake her (during the day), i have to do this with DD sometimes, strip her off to feed, change her bum in b/w sides to wake her again, i used to have to use a cool cloth on DD1's feet because she was REALLY bad at doing that...
She would feed like 5min, fall asleep... go to bed and be up 20min later hungry again.

Trillians ideas are perfect about the snack feeding later at night.