Mucous stuck between most and throat.

Hi all, My daughter is 5 yrs old. She had cold and cough a few weeks back and was treated with azithral. She got better after. For the last few days she has a nose block where it feels like the mucus is stuck between nose and throat. Her ears tickle sometimes as well. No running nose, cough or cold otherwise. Just this. There's also vibration in chest while she breathes in the night especially. She snores mildly on and off. She's on montair lc for the last 15 days, 5 ml on advice of doctor. She seems to need it every 6 months when the weather gets worse. But despite that, she's got this now. How can I help her. Please let me know. I don't want her to fall sick again and go through more meds please. Thank you.