Riedl received her diploma degree in physics from the University of Erlangen-Nuremberg, Germany, in 2001. Her diploma thesis was on (1+1)-dimensional quantum field theoretical models and massless mesons in dense nuclear matter at zero temperature. In 2002, she switched her research focus to experimental particle physics and worked at DESY (Hamburg, Germany) on HERMES data. She investigated the tensor structure of polarized deuterons in deep-inelastic electron-deuteron scattering and received her PhD with the University of Erlangen-Nuremberg in 2005. A fellowship with INFN Frascati (Italy) and a postdoc association with DESY allowed her to continue her research at HERMES. She participated in the commissioning and operation of the HERMES recoil detector and lead the analysis and publication of hard-exclusive data collected with this detector. From 2008 to 2010, Riedl was the deputy analysis coordinator of HERMES. In 2011 and 2012, she worked from DESY as main data quality manager for CMS, one of the LHC experiments at CERN, and contributed to the analysis of the Higgs-boson decay into two tau-leptons and successively into muons.
Riedl joined the Department of Physics at the University of Illinois as research assistant professor in 2013. In 2013-2015, she was the project coordinator for a detector upgrade for COMPASS at CERN (Geneva, Switzerland / Prevessin, France). She organized the prototyping, construction and assembly of a large-area planar drift chamber (DC5). The DC5 detector was constructed in the US, mostly at the Nuclear Physics Laboratory. This would not have been possible without a small army of undergraduate students. The detector parts were shipped to CERN in fall 2014 and assembled. DC5 was installed into COMPASS in May 2015 and has been successfully collecting valuable data since then. Riedl is currently the co-covener for the COMPASS polarized Drell-Yan program and the COMPASS technical coordinator. She is coordinating allocations on the NSCA supercomputer Blue Waters to process the many petabytes of COMPASS data.