Russell Brand's ex-girlfriend Isabella Brewster is set to become a mother for the first time.

The former talent agent announced the news that she and her new husband, New York Knicks basketball star Baron Davis, are expecting a baby as she marked his 35th birthday on Sunday (13Apr14).

In an Instagram.com post, she wrote, "Aayyee Aayyee (sic) Happy Birthday to my Love, Husband and Baby Daddy. Love You!"

The baby news emerges almost three months after the couple tied the knot in January (14).

British comedian Brand dated Brewster, the sister of Fast & Furious star Jordana Brewster, in 2012.