My sneezes are that of a shotgun blasting. Its a full body experience, and quite honestly I dont need to change it, for that has always been how I sneezed. Coughs are just that, a cough, there is no gendered portion there for it. But there may be any justification to try and put some feminine voice to it, would be challenging, but would technically have to practice.
I've heard too many sneezes, and cannot correlate gender to each and every one of them. A high school friend of mine sounded like he would say horses every time he sneezed, or those super high pitched mousey sneezes, from the burliest of men that I've known, or similar to my own shotgun blasting sneezes from many others.
Dare I say to cough and sneeze to your hearts content.
Kate <3