Bukit Brown is a Chinese Cemetery. That being said, it has many cultural material and references that is representative of Singapore, an entrepot between East and West. Angels statues are rare in Bukit Brown and so far i only 2 compared to the tombs with Angels adorning the tomb that you will likely find in Western and/or Christian cemeteries.
The first pair is from the tomb of Mrs. Choa Joon Hean (Madam Cheong Swat Leh).
The second pair is from the tomb of Mr. and Mrs. Teo Chin Chay.