She was educated at Sydney Girls High School and trained as a teacher, graduating from the University of New South Wales with a Bachelor of Arts.

Janette issued a rare public statement denying the allegation as "not only wrong but deeply offensive to me".

[4] John Howard said at the time that he would leave politics immediately if it seemed necessary in the interests of his wife's health.

According to John Howard's biographer Pru Goward, Janette "lives and breathes" politics.

Although she rarely made any public comment on political issues, she did break this pattern by deciding to speak out against Kevin Rudd during the 2007 election campaign.