How do I prompt for more than one members to register on the form?

I am creating an athletic membership registration system. In many cases, there are multiple family members needing to register? After the first member registers from a family, how do I include a filed to ask "Is there another family member that needs to be registered?" I don't want families to have to complete registration forms multiple times. 

The configurable list widget should help you in achieving your requirement. Please refer to the guide below that can help you with setting up the widget on your form.

https://www.jotform.com/help/282-How-to-Set-Up-the-Configurable-List-Widget

Please give it a try and let us know if you need any further assistance. We will be happy to help.