Los Angeles ( CNN ) -- The scheduled arraignment of a California woman charged with murder for allegedly pushing her 7-month-old boy off the fourth story of a parking garage was delayed Thursday , a district attorney 's spokeswoman said . The arraignment for Sonia Hermosillo -- once planned for Thursday -- has been pushed back to Monday , said Farrah Emami , a spokeswoman for the Orange County District Attorney 's Office . Authorities initially charged Hermosillo , 31 , of La Habra , California , with attempted murder . But after the boy died Wednesday , prosecutors upgraded it to one felony count of murder and one felony count of assault on a child with force likely to produce great bodily injury resulting in death . If convicted , Hermosillo would face a maximum sentence of 25 years to life in state prison , according to the district attorney 's office . The incident occurred Monday at a parking garage at the Children 's Hospital of Orange County . A witness saw the baby fall and called police . Investigators interviewed several witnesses and reviewed a surveillance video from the garage . The image of a license plate on a 2000 Chevy Blazer seen leaving the garage shortly after the incident led police to Hermosillo . Authorities found an empty child seat in Hermosillo 's vehicle , according to a police statement . The baby had medical conditions that required regular treatment at the children 's hospital , the district attorney 's office said , and he wore a helmet for one of his medical conditions . `` Hermosillo is accused of removing the victim 's helmet and pushing her baby from the parking structure with the intention of murdering him with the four-story fall , '' the district attorney 's office said . She then walked inside the hospital , validated her parking and left the scene , the office said . `` Baby Noe , '' as the district attorney 's statement referred to the infant , was critically injured and died Wednesday at the University of California-Irvine Medical Center . The district attorney 's statement said Hermosillo has two other children . CNN 's Jillian Ohlenschlaeger contributed to this report .
NEW : The arraignment is now scheduled for August 31 , says a a district attorney 's spokeswoman . The baby , who required frequent hospital ##ization , died on Wednesday . They say the mother pushed the baby , validated her parking and left . Hermosillo , who was expected to be released Thursday , has two other children .