At Oprah's Live Your Best Life Walk on May 9, the new Weight Watchers spokesperson will sing "Happy Birthday" to the daytime diva in honor of O, the Oprah Magazine's 10th anniversary.
“Spending my first Mother's Day at the Live Your Best Life Walk is a really fun experience to encourage others to get moving and help support the benefiting charities,” Hudson, 28, told PEOPLE.
"Weight Watchers has helped me learn the importance of activity and I have seen the benefits that leading an active lifestyle brings – which is a big help when I'm busy running after my son!"
Once Hudson finishes walking with thousands of participants through New York City, she'll be running back to her fiancé David Otunga and their 9-month-old son David Jr.
"Following the walk I plan to spend my first Mother's Day enjoying time with my family," says Hudson.