Tiffani Thiessen has revealed she and husband Brady Smith are expecting their second child after much persuasion from their four-year-old daughter Harper.

Thiessen former star of 'Saved by the Bell' has revealed she and husband Brady Smith are expecting their second child and admits their four-year-old daughter Harper can't wait to have a younger brother or sister.

Tiffani Thiessen has revealed she and husband Brady Smith are expecting their second child

Alongside an image of her family on Instagram, she wrote: "We are excited to announce the news that we are expecting. Harper could not be more thrilled to have a sibling and a playmate."

The 40-year-old star - who married 'The Jensen Project' actor Brady in 2005 - previously revealed that rather than being worried about having to share her parents' attention, Harper has been desperate for a sibling.

Speaking about her and Brady's decision to try for another baby, Tiffani said: "With Harper, it happened right away so I'm hoping it'll be easy this time around.

"Every day she begs me to have a baby.

"Every morning she wakes up and days, 'Is there a baby in your belly?' She thinks it grows overnight while we're sleeping. Then she looks at me and says, 'You're not growing a baby, Mommy!' "