Jessica Simpson has the most adorable reason to celebrate today.
The "I Wanna Love You Forever" singer, who turns 40 this summer, took to Instagram to wish her youngest child, daughter Birdie Mae, a happy first birthday on Friday.
MORE: Jessica Simpson claims she turned down Rachel McAdams' role in 'The Notebook'"You have created in me a healing purposeful life to live most fully and love most deeply," she wrote. "With you my soul has been set free to the beauty of pure light. You guide me to shine because your heartbeat connected me to mine."
"Sweet baby girl, you have illuminated all of our worlds with your bright mystical star-bursting smile," the fashion designer added. "I am forever yours, you are forever mine. Life get ready because the both of us were born ready. I love you!"
Simpson is married to former NFL player Eric Johnson. The two began dating in May 2010, became engaged in November 2010 and married in July 2014.
MORE: Jessica Simpson shares adorable family photo from her children's school holiday concertThe couple have three children together, including daughter Maxwell Drew, 7, son Ace Knute, 6, and Birdie. Simpson was previously married to Nick Lachey from 2002 to 2006.