The Tundra Drums reports 29-year-old Marcasandra J. Frank originally faced a second-degree murder charge, but the additional murder charge says she showed "extreme indifference" to human life.
Frank allegedly told an Alaska state trooper that she had drunk a lot of whiskey, but denied beating her son.
Frank is from the southwest Alaska village of Quinhagak, about 70 miles south of Bethel.
Frank had been staying with her three children at an acquaintance's house.
The 3-year-old was initially airlifted to the hospital in Bethel, then flown to the Alaska Native Medical Center in Anchorage, where he was pronounced dead.
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