The Chicago native began her three-year term last month.
She is the fourth woman to hold the post, following the late Justice Mary Ann McMorrow, Justice Rita B. Garman and the retiring Justice Anne M. Burke.
SEE MORE: Judge Mary Jane Theis sworn in as Illinois Supreme Court Chief Justice
Chief Justice Theis joined ABC7 Chicago Monday to talk about her plans for her term, including assisting those who come to court without a lawyer and addressing mental health issues in those who come before the court.
She said it's been a rollercoaster so far in the position.
Theis also discussed how her career led her to this role.