Is there anything i can give my 7 month old baby so she can spit mucus out thats making her cough?

This sucks: If you find any way to teach a 7 month old to "spit", you'll win a nobel prize in medicine. They cannot nor can they be taught to do that at that tender age. You have to suck it out for them. If they cough and/or gag on mucous and you can hear it in the back of their throats or in their mouths, take the bulb syringe for nose sucking and use it in mouth & throat. This will clear the secretions.