Two Aurora siblings admitted Thursday to felony neglect and abuse of their mother in 2011, which resulted in the woman having part of her leg amputated.
The guilty pleas from Connie Roberson, 51, and Alan Roberson, 55, mean all three siblings accused in the case have now admitted their role in the crime.
Kevin Roberson, 43, pleaded guilty in late May.
Each Roberson, all of the 1100 block of Randall Road, entered a "cold plea," in which a defendant does not have an agreed upon sentence with prosecutors before admitting guilt and lets a judge made the final decision after hearing arguments of mitigation and aggravation.
Judge Clint Hull will sentence Kevin Roberson July 11 and Connie and Alan Roberson Aug. 9.
The charges carry a sentence of anywhere from probation to five years in prison.
Prosecutors did not reduce the charges against the trio in exchange for the guilty pleas.
The Robersons have each been held at the Kane County jail on $50,000 bail since their arrests in October 2011 after authorities found the victim living in squalor.
Authorities have said that the woman, now 78, was covered in bedsores and had gangrene so severe that her right leg had to be amputated below the knee.
She was confined to a love seat, and also had large open wounds and maggots crawling on her.
Prosecutors have said the trio kept her in the home because they wanted her Social Security checks.
Kane County Assistant State's Attorney Debra Bree said Thursday the woman is now in a nursing home and will not be called to testify at the sentencing hearings.