I found that the infant saline nasal sprays worked the best - it's unpleasant for them for a few seconds, but seems to get "up there" better than the drops.
And, I recently found that Brauers have released a "stuffy nose relief" that can be used from 6 months. I used it on my DD (she was 21 months) and I found it helped - whether it was that, or a combination of everything I can't be exactly sure. But it certainly did no harm.
Other than that, can you raise her head end of the bed a few cms?
Hope she's feeling better soon!