We've learned a lot about Selena Gomez this week. She likes roller coasters . Sheldon rocks her world . Her concerts make great Hiddleswift dates . And she's got a soft spot for cute kids.This latest revelation comes courtesy of an Instagram video posted by the pop star. In it, she dances backstage with 7-year-old Audrey Nethery. Nethery, who has Diamond-Blackfan anemia, has been featured on The Rachael Ray Show and other programs and is known for her love of Zumba.According to Audrey's Instagram, she first connected with Gomez months ago when the pop star posted a message of support on the young fan's Facebook page.