What kind of medical solution or remedy can I give to my mother to stop her from snorting and spitting out mucus?

Almost every morning whenever my mom gets ready to go to work, she does a little throat cough clearing the throat,an annoying noise,snorts like snorting up a nose cold,then spits the mucus out,sometimes not even bothering to clear up sink and just left there.She makes the horrific annoying noise like every about 5 seconds and sometimes if I wake up certain times at night and she does it,I’m not able to go back to sleep and it’s so loud I can hear it through my room.

One time she said she’s only doing that because it was winter but it’s summer now and she still does it.I tried convincing to just blow her nose spit in a tissue but doesn’t listen.What can I give her so she can stop doing this?

Also she only started doing this when we moved to the suburbs which has a lot of trees and she’s 51(and NO she doesn’t smoke).