Police on Tuesday evening identified the caustic liquid thrown on Medina as sulfuric acid.
A hospital official is talking about the injuries Medina suffered in the attack and her treatment.
The victim in this case has been sedated since the attack early Monday, so investigators still have not been able to conduct a detailed interview, but there are clues including possible video evidence of suspects leaving the crime scene.
"My main purpose for right now is to get the word out. Someone out there has to know something that happened," said Wendy McEvoy, victim's daughter.
McEvoy and her sisters made their appeal in the parking lot of Stroger Hospital where in the burn unit their 47-year-old mother is reported to be in stable condition.
Witnesses told police she was attacked at 6:30 Monday morning, as she was getting into her car parked in the Logan Square neighborhood, by two women and a man who threw caustic liquid on Medina.
A surveillance camera took video tape and still shots of people police suspect may have carried out the attack. So far, no one has been arrested.
"We're asking the public to please, please, it could be your mother, it could be your daughter that this could happen to," said McEvoy.
Investigators have not identified the corrosive substance used in the attack.
A hospital spokesman called the burn unit at Stroger one of the best in the country.
"The first 24 to 48 hours is the most important period for someone who suffers these type of injuries. And during that period we will monitor her closely," said Marcel Bright, Stroger hospital spokesperson.
After seeing the videotape and photographs repeatedly during the past 24 hours, the daughters say they have no idea who the two women and one man might be or why they may have attacked the victim. But the daughters repeated their claim that during the past two months their mother had been the target of several anonymous telephone threats and vandalism.
"Her tires slashed. Radio stolen, window broken. Purse stolen. We didn't think anything of it. We thought random acts of violence, city of Chicago. But this? This is beyond," said McEvoy.
Police have not commented on the case beyond releasing surveillance images. Detectives are waiting for their first chance to conduct a detailed interview with the victim. No word yet on when that might happen.