She was the granddaughter of John Reynell, who is thought to have established the first commercial winery in South Australia,[1] and the cousin of suffragist Elizabeth Webb Nicholls.

Walter Reynell had inherited his father's large estate, and it was there that Gladys grew up and was home-schooled, before matriculating at Tormore House School in North Adelaide.

The following year, at the instigation of her surviving brother Rupert, Reynell (and Preston) began to learn pottery at the Camberwell School of Arts and Crafts in London, with the goal of teaching it to disabled soldiers.

[3] In 1918, towards the end of the war, Reynell and Preston began teaching pottery to soldiers at the Seale Hayne Neurological Hospital in Devon, where Rupert was a surgeon.

[3] In September 1919, Reynell and Preston shared an exhibition of paintings and pottery at Preece's Gallery in Adelaide, which was just becoming established as a center of the city's cultural life.

[3] Running Reynella Pottery single-handed proved difficult, and sometime after 1920, Reynell hired George Samuel Osborne, an ex-serviceman and gardener, as her assistant.

Nonetheless, Reynell and Osborne were married at St Mary's Church, Edwardstown, in 1922 and then moved to Ballarat in Victoria state, where they started Osrey Pottery.

[2] Reynell's reputation was slow to take off, in part because she worked to a great extent isolated from the larger Australian art community (first at Reynella, later at Ballarat).