This sounds a tough one Mick. It's often difficult to contact these people.
The only suggestion I can offer concerning contacts is the contact webpage for The International Pension Centre here
Details for Fax contact as well a a link for e-mail contact are included.
The other option is that she authorises a third-party here in UK to act on her behalf and then that person handles everything.
I know you didn't ask about the details of claiming, but she should have claimed within 3 months of the death of her spouse. The widows pension no longer exists, it's called Bereavement Payment (one-of immediate payment of £2500) and Bereavement Allowance (a regular payment based on the NI contributions of the deceased spouse and paid for a maximum one year only)
In connection with her state pension, did she make a claim? Does she have any entitlement?
Again it's difficult to comment without having some details. But anyway she should still use the same contact details of International Pension Centre.
Can't suggest anything else Mick.