A police officer responded to a disturbance call at around 1:30 p.m. in an apartment in Quezon City. Upon his arrival, the police officer encountered Sisa stabbing her l-year old child with a kitchen knife. The police officer grabbed Sisa and the latter threw the knife on the floor. Sisa was immediately taken into custody. Despite suffering multiple stab wounds on her back, the child survived. During the trial, Sisa insisted that she can only be held liable for Attempted Parricide because she voluntarily desisted when she threw down the knife. Is Sisa's contention tenable? Explain briefly. (2022 BAR)