WATCH: Reese Witherspoon, Katie Holmes, Peta Murgatroyd and More Stars Celebrate Mother's Day!
“Being a mom is one of the biggest joys of my life. I have learned so much from my 3 kids... patience, kindness, humility, creativity and of course, how to tell a great knock-knock joke!” she wrote. “To my wonderful kids, I love you more than you will ever know (You will figure that out as soon as you have your own kids.) Always know how grateful I am everyday I get to be your mom!!”
For more from Witherspoon, watch the clip below!