Her lawyer said on Monday that the defendant was in hospital.
The party's leader Viktor Uspaskich was present at the court hearing on Monday after missing a number of earlier hearings due to illness.
"Anyone can get ill, we still have no data to prove that the illness is feigned, I cannot give you any other statement," prosecutor Saulius Verseckas told reporters.
The Labor Party is charged with failing to include more than 24 million litas (EUR 6.9m) in income and 23 million litas in spending into its books in the 2004-2006.
The Labor Party's members strongly deny the accusations, saying the case is politically-motivated. The case reached court back in 2008.