Just moved this to the baby section...
Olbas oil on a tissue in the room (not too close to her as it's quite strong) - take her into the bathroom when you shower (steam/humidity helps), keep her as upright as possible (as lying flat exacerbates the snotty issue). You can get saline nose drops (basically sterile salt water) to help clear her nose too... Erm yes and not that she'll give you any choice

but feed feed feed if you're bf!
Squirting BM up the nose apparently also helps but I never got desperate enough to try that

Snuffle babe on your clothes (not hers yet I think) helps too...
Hugs

hope she's feeling better soon - You know what they say, it takes 7 days to clear a cold with meds and 8 days without... xxxx (the worst is the first 2 days I find though)