Julia Stiles welcomes her 1st child with husband Preston J. Cook

— -- Julia Stiles is officially a mom. The actress took to Instagram Tuesday to announce the birth of her first child with husband Preston J. Cook last month.

"Strummer Newcomb Cook, born October 20, 2017. Thanks and ever thanks to the extraordinary Doctors, Nurses and staff at Mount Sinai for helping bring this utter joy into our lives," she wrote. "Hello, World!"

The 36-year-old actress and Cook, a camera assistant, were married earlier this year.

In September, Stiles shared a wedding pic of Cook's hand on her baby bump. "Who doesn't love a shotgun wedding?" she captioned the photo.

In January, she announced their engagement by posting a photo of her and Cook holding hands against a tropical sunset. The photo showed off her unique engagement ring. Stiles captioned the photo, "Best Christmas Ever!"

Stiles met Cook on the set of the 2015 film, "Go with Me."