The teens were on the way home on a motorcycle when the crash occurred.
The girl was able to provide enough information to allow officers to find out her parents' contact details.
He later gave the housekeeper S$200 as a token of appreciation for her honesty.
In a separate incident, she also struck an eight-month-old boy's head and shook him while he was lying down.
Many local netizens were repulsed, but not surprised.
Another student who drove the motorcycle is in critical condition.
After the slaps, her husband tried to scare her by threatening to throw her out of an 8th floor window.
If found guilty, each suspect may be jailed for up to three years, fined, or both.
Passengers are now limited to two power banks each on departing flights.
When the ambulance arrived, Mr Ouyang was unconscious and had no pulse.