The whopping cushion-cut solitaire diamond is nestled on a platinum band encrusted with further diamonds.
Keen to show off the sparkler she got a bright red manicure as she returned home from Abu Dhabi after announcing their engagement on Thursday.
And the former TOWIE star was met with another surprise as her future step-children held up balloons that read "she said yes" to mark the happy occasion.
"The cutest ever," she wrote, sharing a picture on Instagram.
Returning from the glamorous capital of the United Arab Emirates, Kate initially shared a throwback post from their holiday but kept her ring finger hidden.
Earlier this week, former Manchester United star Rio proposed in style, going down on one knee on a helipad on the rooftop of the swish St. Regis Hotel in the capital of the United Arab Emirates.