The family is tight-knit, said Emmanuel, who is the sister of Nadege Theodore and Myrlande Theodore, Guivens’ mother. They all spent New Year’s Day together, going to church and drinking pumpkin soup, a Haitian tradition.

“My sister is a complete wreck,’’ Emmanuel said of Myrlande Theodore. “She lost her sister, her son, her niece all in the same day. And we don’t know about our step-sister.’’

At Broward Health North, friends from Jean-Baptiste’s church and family members came to pray Thursday afternoon.

One man who identified himself as Jean-Baptiste’s father — but declined to give his name — appeared despondent as he spoke of his daughter.

“She is a very smart girl,” he said with tears in his eyes. “But she is in critical condition. She is really bad.”

Max Jean, a family friend visiting the hospital Thursday, described the woman’s condition as grave.

“It’s a 10 percent chance that she might survive because her brain has already shut down,” Jean said. “She is in a coma.”

Jean-Baptiste immigrated to the United States from Haiti in 2006, and she graduated from high school at age 17, her father said. She dreamed of being an anesthesiologist.

Meanwhile, BSO and Florida Highway Patrol continued investigating the accident that caused Theodore’s vehicle to tumble off the highway.

At 10:12 p.m. Wednesday, two calls came in reporting a traffic collision. But the callers gave different locations — with one stating that the collision occurred at the Hillsboro Boulevard exit, and a second putting the scene at the Southwest 10th Street exit.

Police said it took officers about four minutes to locate the scene of the accident, and another 10 minutes for divers to get in the water.

An FHP report said the 2000 Lexus RX 300 careened off the highway just south of the Hillsboro Boulevard exit in Deerfield Beach after colliding with two other vehicles — a 2012 Hyundai Sonata and a 2003 Nissan Altima.

No one else was injured in the collision, and FHP has yet to charge any of the drivers, identified as Marcelo Mario Costa, 38, of Fort Lauderdale, and Romial Romeus, 37, of Lauderdale Lakes.

Costa could not be reached Thursday. Romeus said he struggled to steer his car to a stop after being struck by another vehicle, and that he did not know a third car had plunged into the lake until after he overheard police talking about it.

Sgt. Mark Wysocky of the FHP said it is too early to tell if excessive speed or alcohol were factors in the collision. It is also unknown if the driver and passengers in the Lexus were wearing seat belts.

Theodore is believed to have been driving the Lexus.

Emmanuel last talked with her sister about a half hour before the accident. She also talked with her nephew, who was nicknamed “Pappy’’ by his family. Guivens told his aunt he’d been looking for a job at the mall that night, but hadn’t found anything.

The last thing Guivens said to his aunt, she said, before hanging up: “I love you.’’

Miami Herald staff writer Nadege Green and Miami Herald researcher Monika Z. Leal contributed to this report.