The former Hills and City star pretty much always gets it right when it comes to fashion so it's no surprise that despite being dressed down, she was looking pretty fantastic for her casual day of retail therapy.
But who really needs to dress up when you have a gorgeous ring like that on your engagement finger?!
Fashion designer Whitney became engaged to TV producer boyfriend Tim Rosenman in November 2013. They met while he was an associate producer on The City but didn't start dating until after the show ended.
"When you work on a show, it's like summer camp and you become really close," Whitney, 29, told SheKnows earlier this year. "We formed this really deep emotional connection and never really acted on it until the show got cancelled.
"We would tell each other, 'If this is meant to be, then it's meant to be.' We knew we loved each other, but we just didn't want to blur the lines."
Tim was most recently a producer on X Factor USA.
Got an iPad or iPhone? Reveal Mag is specially designed to fit!
Stars who've announced engagements in 2014 in pictures:
Copyright: Instagram kayascods