There have been several stories circulating about siblings raised by foster families of different ethnicities. This scenario often arises when their biological families faced financial difficulties in the past. 

A similar tale unfolded for two women of Indian and Malay descent from Singapore, who discovered they were actually biological sisters. Mrs. Thangah Koh, 72, and Mrs. Fatimah Mohidin, 71, had been childhood friends since their early years. 

Both were born into a Chinese family before being placed with separate foster families. When Mrs. Thangah, originally Koh Siew Kiang, was just five months old, she frequently fell ill, causing concern for her father. Consequently, she was entrusted to an Indian family. 

A year later, Mrs. Fatimah, originally Koh Siew Lang, was born with unusually large thumbs, leading the fortune-teller to predict misfortune for her mother. And she was placed with Mrs. Thangah's foster family but was later transferred to a Malay foster family at the age of two months for undisclosed reasons.

"People often commented on our similar appearance and asked if we were siblings. I would say I'm Malay and Thangah is Indian. So how could we be siblings?" Mrs. Fatimah remarked.

Despite being encouraged to play together by their foster families since childhood, they never questioned why. When Mrs. Thangah turned 20 and needed to apply for an identity card, she embarked on a journey to rediscover her biological family of Chinese ethnicity. 

This was part of the process of obtaining Singaporean citizenship, as there were no official records regarding foster children back then. Accompanied by her foster mother, Mrs. Thangah finally arrived at her biological family's home. 

Initially, Thangah's biological mother thought the two visitors had mistaken their house, but upon recognizing her daughter, tears flowed. On the same day, Thangah's biological father revealed the truth and confessed to placing an advertisement in a Chinese newspaper in search of his daughter, but to no avail.

Like Thangah, Fatimah's foster family never disclosed her origins, and she simply accepted her circumstances. "Things were different back then, so we just accepted it. My biological siblings are very kind. Our bond grows stronger as we grow older," Fatimah said.

Their biological father also expressed regret for relinquishing both his daughters but harboured no intentions of reclaiming them from their foster families. Their families have since formed close bonds and celebrate holidays together.