Jo was the daughter of Tarquin (Tony) Hartman and his wife Caitlin. She arrived in Ramsay St looking for her half-sister Annalise.

The girls had very different personalities, with Joanna being as uncomplicated as Annalise was 'high maintenance.' While Annalise went into a fit of embarrassed rage when she discovered that the father she'd never met was in fact a female impersonator, Joanna calmly accepted her father's fondness for sequins and show tunes.

The girls' love lives also caused problems. Annalise wasn't best pleased when Jo started dating Mark Gottlieb, Annalise's ex. It developed into something of an obsession if I remember, he admitted that it was nothing more than a fling and Jo eventually accepted that it was going nowhere.

Despite being the more grounded one of the two, curiously, it was Joanna who ended up marrying into money. She tied the knot with Rob Evans; a rich student in her aerobics class. True to form, however, it wasn't the riches she was interested in and she left the marriage when it turned out to be loveless.