By Brendan O'Brien

(Reuters) - A woman convicted of the 2004 starving death of a nine-year-old boy is scheduled to die on Wednesday by lethal injection at a Texas state prison, authorities said.

Lisa Ann Coleman, 38, would be the second woman executed in the United States this year and the 15th since the U.S. Supreme Court reinstated the death penalty in 1976.

Coleman is scheduled to be put to death after 6 p.m. Central Time (7 p.m. EDT) at the state's death chamber in Huntsville. She would also be the 517th prisoner put to death in Texas, the most of any state since 1976.

Investigators were called to Coleman's house in July 2004, where they found Davontae Williams dead with a disfigured ear, swollen hands and ligature marks on his wrists and ankles, according to court records.

An autopsy determined that Williams, son of Coleman's long-time girlfriend, Marcella Williams, had died from malnutrition and pneumonia and weighed just 35 pounds, court records said.

He had been beaten with a golf club and bound by an extension cord, investigators found. His body also showed signs of having been treated with over-the-counter medications, ointments, creams and bandages, court records said.

There was evidence that suggested he was fed chicken noodle soup and Pedialyte before he died, but a doctor testified that the food he received was "inadequate ... too late, and possibly too much," court records said.

Coleman was convicted of capital murder by a jury in 2006 and sentenced to death. Williams also was convicted of capital murder. Williams was sentenced to life in prison and is eligible for parole in 30 years, according to prison records.

(Reporting by Brendan O'Brien in Milwaukee; Editing by Sandra Maler)