On her first appearance as a three-year-old she was beaten by Pilgrimage in the 1000 Guineas at Newmarket but reversed the form with that filly to win the Oaks at Epsom a month later.

Her dam, Chevisaunce, was a daughter of Paradigm, an outstanding broodmare who also produced the Triple Crown winners Lord Lyon and Achievement.

Jannette was trained by Mathew Dawson at his Heath House stable in Newmarket[2] and ridden to her important successes by Fred Archer.

[1] At the Houghton meeting two weeks later she carried a seven-pound weight penalty and won the Criterion Stakes by a neck after a prolonged struggle with the filly Clementine.

The race was run in fine weather, after early heavy rain, in front of a large crowd which included the Prince of Wales.

[13] At York Racecourse in August, Jannette returned to competing against her own age and sex and won the Yorkshire Oaks very easily from her only opponent, leading to heavy betting on the filly's prospects in the St Leger.

[18] At Newmarket in October Jannette ran against her stable companion Silvio, the 1877 Epsom Derby winner in the Champion Stakes.

Silvio led from the start until Jannette moved alongside him in the final quarter mile and the two Dawson runners drew away from the field.

[20] In June 1879, Jannette started 5/1 third favourite for the Gold Cup but finished a distant fourth of the six runners behind Isonomy, Insulaire and Touchet.

[22] In August, Jannette finished third to Rockhampton and Touchet in the York Cup, leading to speculation that she had either lost her form, or been fortunate to compete against unusually weak competition in 1878.

In a rough race, she took the lead inside the final furlong before being overtaken by Isonomy in the closing stages and beaten by a head.