She wanted to get away from her husband that s why she said that he would never hurt him again because she was going to kill her son and herself.
she stuffed the door in order the smoke doesn't leak out of the room not because of the sound, and set fire to the wood so the smoke fill the room and they choke with the carbon monoxide so they die in the process. it´s a pretty well know way to commit suicide.
The burning wood would release toxic gas and that is why she closed the windows and stuff the door so that those toxins would kill them since they would inhale them
The towel was to block the smoke coming out. She tries to kill her child and herself by suffocating from the fumes of the fire and the loss of oxygen. As fas as I know most people in fires don't die by burning but from suffocating.
oh , thank you everyone (＾◡＾) I understand now
so the mother put sleeping pills into ye zi's milk. she then stuffed the door with a towel im guessing to block off sound, but why did she lite a fire and dropped it in the burned wood(?) can someone explain I need help ;-;