The unnamed 41-year-old woman had "lots and lots of personality difficulties" and she knew her actions were wrong, psychiatrist David Greenberg told the New South Wales district court.
The woman pleaded not guilty to 21 sex offences on the basis of having a mental illness at the time.
The offences involve 18 counts of sexual intercourse, involving oral sex and vaginal penetration, and three indecency offences during 2009, Australia's AAP news agency reported.
The six victims were aged 11 and 12 and attended the school where the woman worked as a house mistress.
The offences occurred at the school sick room, in the woman's flat and on camping trips.
On one trip, she went into a tent of five youngsters and had a "conversation with the boys in relation to sexual positions, history and locations she favoured", the court was told.
On another trip when five boys were in the tent, she was naked and asked: "Does anyone want a blow job?"
One victim later said the woman had pressurised the boys, saying: "Come on, let's go, don't be a puss", and he "felt like a wimp" until he agreed to have oral sex with her.
Another child recalled that during an occasion when sex continued for about an hour, the woman said she loved him.
In the court, a psychiatrist called by the defence said the woman lacked control over her impulses at the time. But Greenberg disagreed, saying she had a "personality disorder with mixed features" but did not have a severe mental illness.
He said she had paedophilic tendencies but "technically" could not be classed as a paedophile because the behaviour occurred over five months, not the required six months.
She had said she fell "in love" with an 11-year-old boy, said he initiated the conduct, was "flirtatious and persistent", and portrayed herself as fairly passive.
The woman tried to rationalise and justify her behaviour, saying she had been providing sex education. "She also called them 'young men'. Obviously, 11-year-olds are children," Greenberg said.
Deccan Herald is on WhatsApp Channels| Join now for Breaking News & Editor's Picks