You said she had a cold recently and was nursing more at night? Maybe she has developed a pattern of doing this and needs some time to work it out. Try making sure she gets some good nursing time during the day maybe? That cold may have just gotten her schedule off a bit. Also, it's a bummer, but just when you think you've got your babe figured out they usually go and switch it all around, don't they? Hope you get more sleep soon. I'm sure there will be some better advice soon from other posters!