U.S. sailors rescued a family with an ill 1-year-old baby from a sailboat that broke down hundreds of miles off the Mexican coast — boarding them Sunday onto a San Diego-bound Navy ship so the girl could get medical treatment.

The baby girl, Lyra, was in stable condition at 8 a.m. Sunday when sailors helped her, her 3-year-old sister, Cora, and her parents, Charlotte and Eric Kaufman leave their sailboat and brought them aboard the USS Vandegrift.

The frigate was expected to arrive in San Diego midweek, Coast Guard Petty Officer 2nd Class Barry Bena said.

The Kaufmans were two weeks into a sailing trip around the world when Lyra developed a fever and a rash covering most of her body and wasn't responding to medications. After their 36-foot sailboat lost steering and communication abilities about 900 miles southwest of Cabo San Lucas, Mexico, they sent a satellite call for help to the U.S. Coast Guard on Thursday.

Inoperable sailboat sinks

Four California Air National Guard members parachuted into the water and reached the boat Thursday night. The crew stabilized the girl and stayed by her side until the Navy frigate arrived at about 1 a.m. Sunday.

Sailors waited until daylight to move the family from their inoperable sailboat, "Rebel Heart," which authorities were in the process of sinking Sunday because it was taking on water, Bena said.

It was still not immediately known what illness the girl may have had.

They were very overcautious. They're not new at sailing. - Sister of Charlotte Kaufman

Before the family left for the trip, Lyra had salmonella poisoning, but doctors cleared her to travel after she was healthy again, said Charlotte Kaufman's sister, Sariah Kay English.

When her sister first mentioned plans to sail with two young children, English recalled, "I thought it was nuts."

But English said the couple was always careful. Eric Kaufman is a Coast Guard-licenced captain who introduced sailing to Charlotte Kaufman during one of their early dates.

"They were not going into this blind. I knew they were doing this wisely," English said.

English initially was in daily email contact with the family but realized something was wrong when the communication stopped several days ago.