Nakon što je diplomirala, Mullerova je počela raditi kao prevodilac za jedno industrijsko preduzeće, ali je otpuštena 1979. nakon što je odbila postati doušnik za tajnu policiju Securitate.
Following Muller's graduation, she worked as translator in an industrial enterprise, but was fired in 1979 after refusing to become an informant for the secret police, Securitate.