First, this is an open forum so you would be advised to remove your wife's phone number for security reasons.
Here is the information you want from the section on Roaming at the top of this forum.
If you're abroad and roaming isn't working at all for you, the same team will be able to look into it for you. They can be reached on +447953967967. The team can turn this on from their side. Once this has been done, give your phone a hard reboot (popping the battery out of the phone while it's turned on ) to allow the sim a connection refresh.
We'd also suggest a manual network search to connect to all available networks.