What do you mean by "the software I purchased"? The tag below your question indicates that you are using TurboTax Online. That is not software that you purchased, even if you paid for it. A TurboTax Online account can be used for only one person (or one married couple filing jointly). To do a tax return for another person you have to use a different account or create a new account.
But if you purchased TurboTax desktop software on a CD or as a download, and installed it on your computer, you can do as many tax returns as you want to. On the first screen when you start the TurboTax program, click the button that says "Start a New Return" (not Add a Person). To get back to that screen, select "New Tax Return" on the File menu (not the File tab).
