She's too busy skiing.
"I'm sure there are a lot of people who have already counted me out and doubt my return," the Olympic gold medalist told PEOPLE on the heels of a promising return to the slopes on Thursday, Vonn's first time on skis since badly injuring her right knee during a downhill race in France last December.
"However, even though I've only been on skis for a few days, I can tell you that they are underestimating me."
The most accomplished female skier in U.S. history, Vonn, 29, underwent ACL reconstructive surgery in January and has spent the last nine months painstakingly working to regain strength in her knee.
"It was incredible to be back on snow," she said. "I wasn't even a tiny bit nervous to start skiing again, I was just excited. When I'm skiing, I'm happy."
No stranger to overcoming setbacks – Vonn suffered a serious ski accident in February 2013 and underwent surgery to repair a torn ACL and tibial fracture – Vonn credits her family, friends and Tiger Woods, her boyfriend of nearly two years, for helping her stay positive.
"It has been extremely important for me to have the support of my friends and family throughout both of my comebacks," she said. "It's not easy to continuously believe in yourself when everything seems to stack up against you, but with Tiger and my family's support I was stronger and they helped keep me going. Win or lose, they are always there for me."
With an eye on defending her Olympic gold medal in the downhill at the 2018 Winter Games in South Korea, Vonn hopes to return to competition in December.
"I have worked extremely hard and I am incredibly motivated," said Vonn, who was recently named a Youth Winter Olympics ambassador for the 2016 Games in Lillehammer, Norway. "I will be back."