Born in La Crosse, Wisconsin, Magnus-Stinson earned a Bachelor of Arts degree from Butler University in 1979 and a Juris Doctor from the Indiana University Robert H. McKinney School of Law in 1983.

[1][2] From 1983 until 1990, Magnus-Stinson worked as an associate for a law firm in Indianapolis.

From 1991 until 1995, she worked for then-Governor Evan Bayh, first as an executive assistant in 1991 and then as Counsel to the Governor from 1991 until 1995.

After Magnus-Stinson underwent a series of interviews with officials from the United States Department of Justice and the Office of the White House Counsel, President Obama on January 20, 2010, nominated Magnus-Stinson to the seat on the Southern District of Indiana, to replace Judge Larry J. McKinney, who assumed senior status on July 4, 2009.

The United States Senate confirmed Magnus-Stinson by a voice vote on June 7, 2010.