A Hartland girl with cancer, whose story went viral earlier this year, was surprised Thursday by volunteers who built her a dream bedroom.Emma Mertens, 7, was diagnosed with a rare, inoperable tumor on her brain stem in January. Her story captured the hearts of millions of people when her family asked for photos, emails, cards and social media posts of people's dogs to cheer Mertens up. Special Spaces is a not-for-profit organization that creates dream bedroom makeovers for children with life-threatening illnesses. When they saw Mertens' story, they asked her mother if they could step in. "The main purpose of Special Spaces is to make children feel happy and safe and give them a place to heal," said Monica Jurken, the director for Special Spaces Wisconsin. "They're going through a lot, they just need some extra love and that's what we're here to give."Over the course of two days, a group of volunteers with Special Spaces, Magic Productions, Roman Electric, Closet Concepts and Baird renovated Mertens' room. They staged a big reveal Thursday when Mertens and her family came home from a trip to the Wisconsin Dells. WISN 12 News was the only station there to capture Mertens' stunned response. "I am just so grateful so many people from around the world came out to embrace Emma," said Tammy Mertens, Emma's mother. "We are very grateful. I don't even know how to say thank you."After the reveal, a group from the Humane Animal Welfare Society brought dogs for Mertens to play with outside. You can follow Emma's story and post photos of your dog on her Team Emma Facebook Page.