Police have not yet ascertained the motive behind her attempt at suicide, the official said.
According to Metro officials, the incident took place at 1.08 pm at Janakpuri East Metro station, as the train was heading to Noida City Centre Metro station from Dwarka.
"There was no delay in the metro train service due to the incident. The woman was shifted immediately from the station. Since it happened in a non-peak hour, the trains were running in at ten-minute frequency," a metro official told IANS.
In an effort to prevent suicide attempts at the elevated Metro stations, the Delhi Metro Rail Corporation (DMRC) has raised the height of platform railings. About 90 metro stations in the city are elevated.
DMRC covers 190-km length of tracks and 145 stations, including the Airport Metro Line. It ferries about 2.3 million commuters on weekdays.