Authorities were alerted to a suspected theft from an outlet in the Terminal 3 departure transit area on June 2 at around 2:25 p.m.
Using CCTV footage, officers from the Airport Police Division identified and located the two suspects within an hour, The Straits Times reported.
Both women were detained before they could leave the country.
The younger woman was found in possession of a purse, while a black haversack and a bottle of perfume were discovered in the older woman's luggage.
The total value of the stolen items was estimated at S$635 (US$493).
Both will be charged in court on June 10 with theft in dwelling. If convicted, they face up to seven years in jail, a fine, or both.