Female lawyers were not common at the time and reportedly, when she interviewed at several law firms after graduation, the qualification they were most interested in was her typing ability.
In 1972, Riley became a Wayne County Circuit Judge and in 1976, she became the first woman to serve on the Michigan Court of Appeals.
On December 9, 1982, Republican governor William Milliken nevertheless appointed Riley to the Court to fill the vacancy caused by the death of Justice Blair Moody Jr. on November 26.
Not only had Riley been rejected by the voters, but Milliken was also leaving office in less than a month, and newly elected Democratic governor James Blanchard argued he should be allowed to make the appointment to replace Moody rather than Milliken.
Blanchard replaced her with U.S. District Court Judge Patricia Boyle.