How long to get back to sleep?

Erin

How long does it take your babe to get back to sleep after nursing? Mine is 4 weeks old and wakes somewhere between 3-4 am to feed. It takes only 20 minutes or so to nurse, but over an hour to get her back to sleep. At that point I have another kiddo to get up at 6 and the baby again eats right after that. I go back to work in 2 weeks and am not sure how to make it from 3 am on with no sleep!