The former Saved by the Bell and Beverly Hills, 90210 star and her husband Brady Smith welcomed a son on Wednesday (01Jul15).

Thiessen took to Instagram.com on Thursday (02Jun15) to share a sweet snap of her four-year-old daughter, Harper, holding her new baby brother in her arms, and the actress added the caption: "Yesterday Harper got a little brother! We are so excited to introduce Holt Fisher Smith. Our perfect sweet little man."

Thiessen and Smith wed in 2005.