The British royal is known for championing high street as well as designer fashion, but didn't accept a package sent by the reality TV star and her sisters Khloe and Kourtney from their new Dorothy Perkins range.
A source told The Examiner magazine: "Kate is hardly going to turn up for an event with the queen in a cheap leopard-print miniskirt or gold sequined jacket."
Kim was also said to be keen to meet with Catherine - known as Kate Middleton before marrying Prince William - while she was recently in London, inviting her for tea.
A source said: "The Kardashians want to be as big in the UK as they are in America, and think associating themselves with the Royals, especially Kate, will help them achieve that.
"She hoped Kate might be seen wearing one of the designs out in public, which would give their fashion credentials a huge boost."
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Kim, 32, has been vocal about how much she loves Catherine's fashion choices in the past.
She said: "Kate seems like a really sweet person and she's a princess. We love her sense of fashion. She could wear our looks and team it with one of her hats."
A representative for the Duchess made clear most gifts she is sent are returned.
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They told website MailOnline: "In general terms, the policy of The Duke and Duchess of Cambridge is not to accept any unsolicited gifts unless the sender is known personally to His or Her Royal Highness.
"Any such gifts are returned to the sender with thanks and an explanation of Their Royal Highnesses' policy."