Melissa Joan Hart is expecting her third child. The former Sabrina the Teenage Witch star - who turns 36 today - announced the news on Twitter by posting a picture of her visibly pregnant self along with sons Mason, six, Braydon, four, and husband Mark Wilkerson.

"(Early) Happy Birthday to me! And baby makes 3!" she wrote on her Twitter.

A source told Life & Style magazine the Melissa & Joey star could not be happier about the latest addition to the clan. "She's really excited and is starting to show. You can barely tell, but there's a teeny-tiny little bump," the insider said.

Melissa - who married 35-year-old musician Mark in 2003 - had always hoped to have a large family, and has even been looking in to the possibility of adoption. Following the birth of Braydon, she revealed, "We definitely want to add to our family. We're interested in adopting as well. We're just starting to explore that. Since I was little, I knew that I wanted to have children. I'm the oldest of eight kids, and I have always liked the idea of a big family."

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