The Hennepin County medical examiner's office said Tabitha Markle died Monday at Children's Hospital in Minneapolis, the Minneapolis Star Tribune reported.
The child was under water for 15 minutes after the SUV being driven by her father broke through the ice on Lake Minnetonka in suburban Minneapolis.
The county sheriff's office said it was investigating the incident and "will determine if alcohol was involved" in the Friday night incident, the newspaper said.
Sheriff Rich Stanek said Saturday there were indications the girl's father, Jonathan L. Markle, 41, had been drinking, but blood-alcohol test results were not yet available.
Besides Tabitha, Markle was accompanied by his wife, Amanda, 31, and their 2-year-old daughter, Isabelle, when their vehicle broke through the ice. Everyone but the infant survived.
The family had been to a restaurant earlier.