Roberta is a resident of Soleanna in Sonic the Hedgehog (2006). She appears to be a safety officer from the warehouse district in New City. Therefore, it is her duty to keep an eye on the safety of others and to watch out for any hazards that might endanger the warehouse or any nearby civilians.
In Silver's story, Roberta gives Silver his ninth Town Mission. A malicious army of Badniks have broken into the warehouse district and are trying to detonate the highly explosive red barrels, most likely with the intention of causing mass death and destruction. In order to protect the surrounding area, Roberta asks Silver to destroy these robots and prevent them from causing the barrels to explode.