"I was pretty young but have a vague recollection of running around getting ready because my mother had an hour and a quarter's notice," Mr Eastwick said.
"She got a call from whoever was in charge and was told the Queen Mother would like to come and visit the farm.
"She managed to get everyone together dressed up, cleaned up the Land Rover for a farm tour and make some pikelets."
Family legend has it that Jonny waltzed into the sitting room where his parents were serving tea and pikelets, politely tugged on the Queen Mother's sleeve and told her he had wet his pants.
The lady-in-waiting turned to his mother, said, "I'll get this", and escorted him away.
"One of [the Queen Mother's] comments to my mother was that she absolutely loved the way she was entertained and felt very much at home."
The 1150ha Ohariu Valley beef and sheep farm - purchased by Mr Eastwick's grandfather in the 1920s - is still owned by the family, who recently launched their high-end export meat, Boomrock Premium Coastal Lamb.
Mr Eastwick's parents have now moved into the inner Wellington suburb of Thorndon and the coastal farm is run by him, his wife Mildy and their children Jeks, Tommy and Harry.
Since the Queen Mother's visit, the family have added a BMW racetrack on site, a shooting facility and The Lodge private function centre.
"The Queen Mother wanted to experience a farm run by a normal New Zealand farming family, which it was and still is," Mr Eastwick said.
"And here we are in 2014 and her great-grandson is here and going to have some of our lamb."
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