Hi amy,
I have a linksys router, but it is the BESFX41 model. Should be similar to what you got at least for settings editing since we both got a linksys router.
I am going to assume that you have not changed any settings on router.
1. Go to 192.168.1.1 (type this into address bar of your web browser, and open it like you go to any standard website)
2. For me, a login box would appear which asks for username and password. In the place where you type a username, I would leave blank and in the password box, type
admin (So you no username and admin is the password ... If this is not working, maybe you ask your nephew and his dad to see if they changed username/password or they can assist you in your troubleshooting)
3. When you reach the control panel, click Application & gaming. Click on "UPnP Forwarding" then find FTP 21 and HTTP 80. Make sure you click on the enable checkbox to the right of the FTP21 and HTTP 80 lines.
4. Hit save settings on the bottom of the page. For me, it will say that settings successfully saved and will go back to the previous page in 10 seconds, maybe you get something different but i don't know what you will see.
5. Reset computer and try your website again!
At least, this is how it works for my router, hope it works for you