Donates 'Super Soldier' Breast Milk

Serena Williams recently found herself in New York with extra breast milk, but rather than lugging it all home, the tennis G.O.A.T. did something awesome -- she donated it to moms and babies in need!

The 23x Grand Slam singles winner told the story Wednesday on Instagram.

"On a recent trip to NY I had leftover breast milk," the 42-year-old wrote in the caption. "After going through a screening I was able to donate it instead of taking the milk home."

"I know so many amazing women that adopt or are unable to make milk. It felt amazing. BTW Someone out there is getting some super soldier milk. \ud83e\udd2d"

This isn't the first time Williams -- who had her second child in August -- and her breast…