In 1929, aged 19, Bate and her friend Betty James opened a dress shop named "Magg" on
Little Collins Street, funded by a loan of £150 () from her father. The shop was originally based in an upstairs room, but soon moved down the street into an old blacksmith's shop which they renovated. She and James were featured in the
women's section of
The Herald as "two well-known Melbourne girls who have joined forces and gone into business", and she later recalled that she was the only girl from her class at Toorak College to have "gone into trade". Her mother eventually insisted that she close the shop. Upon liquidating her stock she ended up with a profit of £1,500 (), which she used to fund a trip around the world. Bate worked in marketing for her father's food manufacturing business during
World War II, after separating from her first husband. She designed labels and advertisements for its Tandaco trademark, incorporating plastic recycled from munitions factories into its packaging. She was the head designer while Grounds looked after the business aspects. The business was immediately successful, benefiting from strong interest in designer wear after the end of wartime clothing rationing. A collection of Bate's dresses is held by the
National Gallery of Victoria. In 1964
The Canberra Times reported that she regarded her "greatest fashion triumph" as a mother-of-pearl silk skimmer dress worn by
Tania Verstak, the winner of the
Miss International 1962 pageant. She designed the Australian women's uniform for the
1968 Summer Olympics in Mexico City, providing one design in "
wattle yellow" for official use and another in "Olympic green"
crimplene for casual wear. In 1966, Bate was said to favour monochromatic "total look" dresses that were well-cut and "strongly styled". She praised the
miniskirt style that
Jean Shrimpton had
controversially introduced to Australia the previous year, although noting that it did not suit all figures, and expressed her disdain for hats. ==First marriage and children==