Mueller, who is suffering from pneumonia in both lungs, is still in the intensive care unit and is expected to remain for two or three more days, according to her mom, Moira Fiore.
"Brooke came in at the very last minute because sepsis from an infection following surgery for her impacted wisdom tooth had invaded her system, and her organs were starting to shut down," Fiore tells PEOPLE. "Today her lungs, kidney and liver functions look better. But doctors are still worried about her low blood pressure."
Mueller's husband, Charlie Sheen, visited his wife in ICU Thursday morning. The Two and a Half Men star, who is now allowed to have contact with his wife in the hospital despite a protective order against him stemming from his domestic violence arrest on Christmas Day, held Mueller's hand, put his arms around her and told her to just get better.
"They were lovey-dovey and touching each other," Fiore tells PEOPLE. "They are a perfect couple when neither of them is drinking."
Meanwhile, the Colorado judge who partially lifted the restraining order imposed upon Sheen, also agreed to postpone the modification hearing (which had been set for Friday) on that original order.
"The judge will now hear the case at 2:15 p.m. Feb. 8 in Aspen," Mueller's lawyer Yale Galanter, tells PEOPLE. "It gives Brooke time to get well."