Anna was responsible for the gestation of naturally occurring foodstuffs during her tenure in the Rivet City science lab, where she worked under Doctor Li. Soon kidnapped by the Enclave, Anna Holt was "forced" to help the Enclave in their experiments at Raven Rock. She was astonished by the technology the Enclave possessed and she quickly told them everything about Project Purity. She can be found at Rivet City science lab before The Waters of Life, and at Raven Rock after The Waters of Life, located in a room near the science lab.
The American Dream: She can be found inside Raven Rock, now working for the Enclave. Killing her at this point will still grant negative Karma. Leaving her to be blown up along with Raven Rock will not, however.
The first time you walk into the science lab at Rivet City, Anna can be seen having an argument with Dr. Zimmer about his missing android, and she's telling him that Doctor Li has more important things to do. For first time players, this could be a silent tip to the Replicated Man quest.
Despite her betrayal of Project Purity to the Enclave, killing her in Raven Rock results in bad Karma.
Despite working with Enclave after they take over Project Purity, Enclave soldiers will shoot her on sight after you interact with her.