The five-year-old girl was sleeping in the state run child care centre on May 30 when the woman made futile attempts to wake her up. She then heated a knife in a stove and burnt her right leg.
The child narrated the incident to her parents and they filed a police complaint last night.
The 39-year-old anganwadi worker was arrested this morning and booked under various IPC Sections, including 324 (voluntarily causing hurt by dangerous weapons or means).