As authorities begin to search a North Carolina pond in connection with the disappearance of 15-month-old Evelyn Boswell, her mother has been charged with frequently changing her story and impeding the investigation. Sullivan County Jeff Cassidy said Wednesday Megan Boswell, 18, is charged with one count of making false reports that “impeded our investigations” with various “conflicting, inaccurate statements” over the last week. “Every time we’ve talked to her, her story changed. Every single time,” Cassidy said, calling Boswell’s actions “frustrating.” The false report was made hours after she told reporters she could not take a polygraph test because she is pregnant—a claim Cassidy denied. So far, nobody has been charged with Evelyn’s disappearance, which may have occurred as early as Dec. 10 but was not reported until Feb. 18. The sheriff added the investigation has received over 500 tips regarding the toddler’s location and a search is being conducted at the Wilkes County pond based on one of those tips. The 15-month-old’s grandmother and her companion were previously taken into custody in Wilkes County on charges related to a stolen vehicle.