Here is a couple of very good links to assist you with your issue. Go to this link http://bit.ly/19qGhRY, it is for the Framily plan info. Go to this link http://bit.ly/1qvmUxW, it is for FAQ about the plan. If this is a new account you can go online to sprint.com/shop. Hope this answers your question. We are here to help.
What is the zip code of location? I'd like to double check for store locations in your area. Unfortunately, because you are adding your own equipment, you will not be able to add the new line to Framily online.