In August, Mrs Searle posted two items she had made for baby Prince George - a knitted red cardigan and a traditionally styled cotton sailor suit - to the couple's residence, St James Palace, London.
The card she received had a photograph of Prince William, his wife Catherine and Prince George on the front, and a printed message on the back saying the Duke and Duchess were ''most touched by the thoughtful gift''.
''Their Royal Highnesses are overwhelmed by all the wonderful messages and gifts they have received and send you their warmest thanks and best wishes,'' it read.
Mrs Searle was ''very thrilled'' by the card and would have it, the envelope it came in, and photographs of her handcrafts framed as a memento.
She said she would now be watching media coverage of the couple and Prince George closely to see if he was wearing the garments she sent.
William and Catherine tried to discourage gifts for their son by suggesting people donate to their favourite charities instead.
But they have been inundated with gifts, including an apple tree, a jewel-encrusted charm bracelet that doubles as a fancy holder for a jar of nappy-rash cream, jeans and a hoodie from singer and clothing designer Kanye West, baby-sized cufflinks from Prince Charles' god-daughter India Hicks, and a live baby crocodile (called George) from Australia's Northern Territory state.
Fortunately, palace staff do not have to look after his crocodile. It will live in a Northern Territory wildlife park with two others (called Wills and Kate) and George can visit.
New Zealand's official gift was a hand-spun, hand-knitted merino shawl.
