J. Blalock was a Human Starfleet officer in the 22nd century.
In January 2155, she was listed as a Science officer on one of the directory placards at Starfleet Command's Fleet Operations Center, Sol Sector. His office was located in room #5550. (ENT: "Demons", United Earth directory)
This character was only mentioned in writing.
She was named after Star Trek: Enterprise actress Jolene Blalock, who played T'Pol, the Vulcan science officer aboard Enterprise NX-01.