Try these thing in this order:

• Turn Wifi off on wifes phone and try to get to site with phone.  Does it work?
• If that works figure out how to bypass router (unplug internet service from back of router and plug it directly into computer)
• Try site again.  If it works then problem is with your router.  If not, then ISP may be blocking it.

It is possible that your ISP is blocking a range if IP addresses (sites) due to something they think is malicious.