How do you add multiple text boxes?

example:

Baby: first name box  surname box

You can use the current name field, it has two fields.

You may also use some of the widgets on this link: 

https://widgets.jotform.com/category/multiple_entries

This guide will help you to add it to your form: http://www.jotform.com/help/252-How-to-Add-a-Widget-to-your-Form. 

Hope this helps.