Rush joined the court since last month, but Gov. Mitch Daniels administered the formal oath of office to the former Tippecanoe County judge during the ceremony. Daniels picked Rush in September to replace Justice Frank Sullivan Jr., who stepped down in July after 19 years as a justice.
Rush's daughters, Mary and Sarah, slipped their mother into her official black robe following her swearing-in.
Rush is only the second woman to serve on the court, after Justice Myra Selby, who stepped down in 1999.