She was one of the first female solicitors in Australia, following Victoria's Flos Greig (admitted to practice in 1905) and Anna Brennan (in 1911).
Her brother Joseph McWhinney was completing his Articles of Clerkship at solicitors, Wilson and Ryan, in Townsville and he persuaded her to pursue the law instead.
[1] Although Justice Pope Cooper of the Northern Supreme Court of Queensland disliked the idea of women entering the legal profession, he was unable to find any basis to refuse her and so admitted her to practise as a solicitor on 7 December 1915.
On 23 March 1920, McWhinney married Lowell Mason Osborne and discontinued her paid employment and only did legal work as a community service.
[7] The Queensland Law Society has an annual Agnes McWhinney Award to recognise the contributions of a female lawyer.