FORT WORTH, Texas — When a 14-year-old girl took 14 Benadryl pills in the middle of the night, her older sister called their grandmother for help, wanting to avoid getting in trouble with their parents. “It was scary. She had fractured sentences, hallucinations. Her resting heart rate was 199,” the girl’s mother later said, according to Cook Children’s Health Care System, where the teen was treated in 2020. Two other teenagers also were being treated for Benadryl overdoses at Cook Children’s at the time, after watching online videos on the popular social media platform TikTok. A year and a hal…