So, apparently at one of the finals Martina and the Duchess had a chat and that lead to Martina sharing that she'd not seen her family since she defected.
At the time the Czechoslovakian authorities wouldn't even allow her matches to be shown on tv.
The following year the Duchess personally, and quite publicly, campaigned the authorities to grant her family, inc her mum iirc, a visa to travel. They gave in to the pressure and they got to go to Wimbledon