The monarch is said to believe Kate should have a full-time career before she and Prince William announce their engagement.
A source said: "The queen has had conversations with a few trusted friends about how to tackle what is being called the Kate problem. The queen has admitted she has no idea what Kate actually does.
"Privately she is very concerned about what the repercussions could be if Kate is not in a stable job as and when William is ready to propose. The queen is very aware that it's a serious and long-term relationship. She is of the opinion that Kate should be working.
"She believes in a modern monarchy and feels very strongly that the Royals should be leading by example."
Kate - who announced she wanted to become a photographer after leaving her job at high street chain Jigsaw last year - currently works for her parents' mail-order company Party Pieces.
The source added to Britain's Mail on Sunday newspaper: "It's not what you would call a nine-to-five job. It's an easy number for Kate and basically something to fill her days while she waits for William.
"Over the past few months, she has been at home with her family shooting pictures for the Party Pieces website. She loves taking pictures, but when she said she wanted a career photographing unusual subjects, we didn't expect it would mean pictures of toys."
It was previously rumoured Kate would be trained by royal photographer Mario Testino.
Clarence House have refused to comment on claims the queen wants Kate to find a full-time job, saying: "We don't discuss any speculation about the prince's private life."
TAGS: Europe Queen Elizabeth