Hasrinah Hassan, 35, was first charged last week with a single count of criminal breach of trust of US$11,464 in 2003 while she was employed by the US Government as a consular cashier.
On Wednesday, five more charges were filed against her for allegedly siphoning between US$61,818 and US$144,396 from 2004 to 2008.
Bail of $300,000 was set.
A police prosecutor told District Judge John Ng that only S$5,400 has been recovered.
Hasrinah has been remanded as she was not able to post bail.
A pre-trial conference will be held on May 21. If convicted, she faces a jail term of up to seven years and a fine on each charge.
Accused of siphoning $792k