An autopsy and cause of death are expected to be announced Thursday evening.
Jazmine is the youngest of three children. The mother is in police custody. They are investigating her for allegations of neglect. Charges are pending.
The Department of Children and Family Services says it has had prior contact with the family.
Jazmine was born two months premature. Sources close to the investigation say she had spina bifida. She weighed less than 5 pounds at the time of her death.
"My sister is a good parent, she treats her children very well and there is nothing that she would do to put them in harm's way," said Chenita Bell, Jazmine's aunt.
"We have a 5 1/2 month old baby that was 5 lbs. at death, that's a concern. And now we have discovered that DCFS returned two children into that home recently and couldn't see this mother was in no condition to take care of children," says Harvey spokesperson Sean Howard.
DCFS says the two other children have been taken to a local hospital for evaluation and will be moved into traditional foster care. No further details about the children have been released.
DCFS was most recently in contact with the family on March 18, when the children were allegedly left unattended by Jazmine's father, Jerome Walker. Walker was arrested by Chicago police the same day and faces three charges of child endangerment, as well as charges for possession of a concealed weapon, possession of ammunition, possession of a controlled substance, not stopping at a stop sign and driving on a suspended license.
"She didn't have anything to do with that," says Bell of her sister. "She was at work, he was supposed to have them, be watching the kids."
DCFS indicated in a separate investigation that there was evidence against Walker for child neglect. It's the agency's policy, a spokesperson said by phone, to "keep families united while supplying support." Bell says she knew DCFS was working on a caregiving plan with the mother and an another aunt.
"Kids have their hair done, they had clothes on their back, she made sure they are well fed, it was just that she was sick," says George McCallum, Bell's fiancee. "And all the kids, they were born premature, I think that was the cause of her death."
"This is not as bad as it looks, there is an explanation to all this," Bell says.
"We have a malnourished kid that dies on the way to the hospital, there is no excuse for that," says Howard. "The investigators owe the taxpayers more answers than saying 'Oh, we see these things all the time.'"
The mother is being held at the Harvey Police Station pending the autopsy results.