A Tennessee mom was allegedly driven to drown her daughter in a creek because she had a “rough day” and “wanted time alone,” said police. Brandi Elliott, 33, has been charged with first-degree murder in connection with the death of 7-year-old Piper Elliott Saturday in a Hendersonville, Tennessee creek, said authorities. Elliott allegedly told investigators she was having a “rough day” and “wanted time alone,” so she went outside, only for her daughter to follow, court documents read, WTVF-TV reported. Piper would not “give her what she wanted,” so she took her daughter across the street to a c…