“Sabrina, the Teenage Witch” is getting hitched! In another news exclusive I can reveal that Melissa Joan Hart got engaged to her rock star boyfriend Mark Wilkerson during a holiday family gathering in Lake Tahoe. “We saw the ring before Melissa,” Mark’s mom Jennifer told us. “It’s three carats. It’s gorgeous!” Mark, 24-year-old singer with the band Course of Nature, slipped the ring on his witch’s finger during the early morning hours of December 27, ditching a plan to propose in front of family members after they woke up. “He couldn’t wait,” said Jennifer. Melissa, 26, cast her spell on Mark at the Kentucky Derby last May when she emceed a post-race show featuring his band. “Somebody else in the group was hitting on Melissa and Mark didn’t think she’d noticed him at all,” said his mom. He was wrong. Melissa called him a few days later and they’ve been steady-dating ever since. The Tahoe get-together was the first time Melissa and Mark’s clans met one another and Jennifer said everyone got along great — although Mark’s dad slipped up a few times and called his future daughter-in-law Sabrina instead of Melissa!