(CNN) -- The latest statement from Joan Rivers' daughter gave no new information about the comedian's condition three days after she was rushed to a New York hospital.
"Thank you for your continued love and support," Melissa Rivers said Sunday. "We are keeping our fingers crossed."
Rivers, 81, stopped breathing during throat surgery at a Manhattan medical clinic Thursday morning, according to the New York Fire Department. She apparently suffered cardiac and respiratory arrest during a procedure.
She was listed in critical condition in New York's Mount Sinai Hospital, where paramedics took her by ambulance.
Her daughter's initial statement, made public late Thursday when she arrived at the hospital after a flight from Los Angeles, said her mother was "resting comfortably."
Her next statement Friday also gave little indication of Rivers' prognosis.
"Her condition remains serious, but she is receiving the best treatment and care possible. We ask that you continue to keep her in your thoughts as we pray for her recovery."
Rivers' was undergoing an apparently minor elective procedure at the clinic, which is about a mile away from the hospital where she was taken.
She had been scheduled to perform her comedy act at the Count Basie Theater in Red Bank, New Jersey, the next night.
Michael Lucas, who was in the audience for Rivers' show at New York's Laurie Beechman Theatre on Wednesday night, told CNN that she joked about death.
"She said, 'You know I'm 81 years old, and I could drop dead at any moment and you would be so lucky because you will have a story to tell your friends for the rest of your life,'" Lucas said. "Then she mimicked people talking about what it was like to see her drop dead on stage."
Rivers was in fine form, he said. "There was no sign (Wednesday) night that she was declining. Her show was over an hour long and she never stumbled or even paused to catch her breath."
In 2013, Rivers allowed cameras to record a health scare for her and her daughter's reality show, "Joan & Melissa: Joan Knows Best?"
Rivers said on the show that doctors found a spot on an X-ray after she had a persistent cough.
"We're just not going to be sad about this," Joan Rivers said during the episode. "We're gonna do jokes and be up until we know. That's how I deal with things. I'm not just gonna sit around the next couple of days and go crazy."
Rivers has been open about her health issues. She was diagnosed with osteoporosis in 2002 after a fall down some stairs left her with broken bones, and she became an advocate for screenings for women.
She also admitted to not being as healthy as she could be.
"I try not to be, but I'm a terrible eater," she said. "I wish I could say I eat super-healthy, but I don't. I love junk food -- it should be its own food group -- so I help my bones with supplements and medicine."