SIOUX CITY, Iowa (AP) — A Sioux City woman accused in the death of her infant son has pleaded not guilty to child neglect and child endangerment resulting in death. Rebekah Williams-McCarthy, 24, entered the pleas Friday in Woodbury County District Court, the Sioux City Journal reported (http://bit.ly/1raJmfv ). Earlier court documents filed in the case say Williams-McCarthy failed to take the baby to doctor appointments and did not pick up vouchers for baby formula.