Beyonce's mom posts baby photo for singer's 37th birthday

Sept. 4 (UPI) -- Grammy-winning singer Beyoncé is celebrating her 37th birthday.

The star's mom, Tina Knowles, marked the occasion Monday evening by sharing a throwback picture of a 4-month-old Beyoncé on Instagram. Beyoncé officially turns 37 on Tuesday.

"It's already your birthday where you are," Tina explained in the caption. "So Happy Birthday to the nicest, owner of the most beautiful, generous, loving hearts ever!!!!"

"On this day you were 4 months old and i couldn't even control the excitement and pride and the all encompassing love i felt for you, my first born. I made a vow to love and cherish you everyday. For the rest of my life!" she said.

Tina is parent to Beyoncé and 32-year-old singer and actress Solange Knowles with Mathew Knowles, from whom she split in 2009 after 19 years of marriage.

"The day that you and your sister entered this world were the two best days of my life, hands down! It is a privilege to have carried you two in this body," Tina wrote. "Enjoy your B-Day!!! No one deserves it more!! I love you."

Beyoncé herself is parent to 6-year-old daughter Blue Ivy and 14-month-old twins Rumi and Sir with her husband, rapper Jay Z. She recalled in the September issue of Vogue how Jay Z was a source of strength following the twins' difficult birth.

"We spent many weeks in the NCIU," the star said. "My husband was a soldier and such a strong support system for me. I am proud to have been a witness to his strength and evolution as a man, a best friend, and a father."

Beyoncé and Jay Z will resume their On the Run II tour Sept. 11 in Arlington, Texas.