Guen Aguilar could now be jailed for life if convicted after a trial to begin on May 15, the lawyer Shashi Nathan said.
"Originally she faced a murder charge," Nathan told reporters after a preliminary inquiry at High Court.
"The present charge is one for culpable homicide not amounting to murder. There is a possibility of a life sentence."
Nathan said he did not know why the charge had been altered but it was a huge relief for his client and he would work to convince the court that she should be sentenced to much less than life if convicted.
"Certainly the first thing we need to do is to tell the court that a life sentence would not be fair in this case and we have to show the court through our own arguments and submissions that a sentence below 10 years would be appropriate."
The accused listened to proceedings through an interpreter.
Aguilar, 29, was arrested hours after the severed head and limbs of Jane La Puebla, 26, were found inside a sports bag near a subway station at the Orchard Road shopping district on Sept. 9.
La Puebla’s torso was later found at a nature park.
Nathan first said last October that he would not rule out seeking an amendment to the murder charge against Aguilar after his conversations with her gave the defence team a clearer picture of what may have transpired.