While they were standing in line awaiting their vaccination at the school clinic, Pomping repeatedly pulled the ponytail of Katreena, his 11 years, 2 months and 13 days old classmate in Grade 5 at the Sampaloc Elementary School. Irritated, Katreena turned around and swung at Pomping with a ball pen. The top of the ball pen hit the right eye of Pomping which bled profusely. Realizing what she had caused, Katreena immediately helped Pomping. When investigated, she freely admitted to the school principal that she was responsible for the injury to Pomping's eye. After the incident, she executed a statement admitting her culpability. Due to the injury, Pomping lost his right eye.

(a) Is Katreena criminally liable? Why? (b) Discuss the attendant circumstances and effects thereof. (2000, 1998 BAR)