If she is really struggling perhaps get a GPs advice on what to do. I know a little baby (less than a month old) who got a cold and they ended up taking him to hospital and basically 'sucking' the goo out because it was past the point where he could deal with it himself, and of course it make him not able to sleep and feed well so it was kind of a downward spiral of sickness/tiredness/not enough milk/not enough energy to fight the bug. But if she's got some more sleep today you might have turned the corner on it *fingers crossed*.
The only other thing I can think of was when DD2 had a cold I was trying to shake before surgery was her GP suggested lots of floor play with rolling around and movement to help move the mucus along. She is obviously a lot younger and not really at the rolling around stage but getting her moving on the floor with your help might move things along.