BBC NEWS | UK | England | Oxfordshire | Prince apologises to 109-year-oldWendy Mead, a senior nurse manager at the Grange care centre in Stanford in the Vale, said she was not expecting the Royal visit.
"We received a call and within five minutes, Prince William had arrived," she said.
"It was a total shock, and Catherine was speechless. Prince William came in and she asked if he was real. She squeezed his hand to check."
They chatted about the Prince's great-grandmother, the Badminton horse trials and his cooking.
"He told her he liked making shepherd's pie and said he used a masher to mash the potatoes, but she told him he was doing it wrong - he should use a fork to fluff the potatoes," Ms Mead said.
Catherine Masters has now been invited to a garden party with the Queen at Buckingham Palace on 7 July.
"She's off to buy a new dress and hat," Wendy added.
"We received a call and within five minutes, Prince William had arrived," she said.
"It was a total shock, and Catherine was speechless. Prince William came in and she asked if he was real. She squeezed his hand to check."
They chatted about the Prince's great-grandmother, the Badminton horse trials and his cooking.
"He told her he liked making shepherd's pie and said he used a masher to mash the potatoes, but she told him he was doing it wrong - he should use a fork to fluff the potatoes," Ms Mead said.
Catherine Masters has now been invited to a garden party with the Queen at Buckingham Palace on 7 July.
"She's off to buy a new dress and hat," Wendy added.