MIAMI -

A woman who pleaded guilty to DUI manslaughter in the death of a 68-year-old grandmother was supposed to be heading to prison Tuesday, but the case has been postponed until Wednesday.

Ivanna Villanueva accepted a plea deal in May for the October 2011 death of 68-year-old Eyder Ayala. According to police, Villanueva was driving drunk with a fake ID when she slammed her car into Ayala's vehicle at the intersection of LeJuene Road and Majorca Avenue in Coral Gables, killing Ayala almost instantly.

The delay in court Tuesday centered around Villanueva's incomplete drug test. She will be back in court on Wednesday to retake it.

After she completes the prison sentence, Villanueva will be on probation for 15 years. She was also ordered to donate to Mothers Against Drunk Driving on Oct. 2, the anniversary of the crash, in the amount equal to how old Ayala would have been that year.