Miller and his wife Morgan had been attending a party at the address when the tragedy struck.
Orange County Fire Authority captain Tony Bommarito said paramedics were called but were unable to resuscitate the toddler.
"I think they worked on the baby for a long time," Bommarito said.
Miller later issued a statement via Instagram, describing his family as "beyond devastated."
"Our baby girl, Emmy, passed away yesterday. Never in a million years did we think we would experience a pain like this," Miller wrote.
Miller, 40, is the most decorated skier in US history, with six medals in 2002, 2010 and 2014 Winter Games, including a gold in the super combined in Salt Lake City in 2002. He is also a former World Championship gold medallist and twice won the overall crown in 2005 and 2008.
He married professional beach volleyball player Morgan Beck in 2012. The couple have a son, Edward Miller, born in 2015, a year before Emeline was born in 2016.