Just a cough? If she is congested you can buy this stuff called vapor bath by Johnson, and you can also apply baby vapor rub to her chest if she sounds like she is having trouble breathing, depending on how old she is. I second the zarbees natural meds. They make different kinds and have some for babies under 1. If her nose is stopped up then use some saline spray and suction. You can also use a humidifier if you have one with certain essential oils that may help clear her up. Hope this helps!
I used the zarbee natural medicine line for my girls. It works wonders. Also, in my family there is a chamomile tea that they make that helps a lot too