Reyes' main job is to listen and write down the reports she get from the communications radio. She is rather bright as even with some believable reports, she has the sense to have the Courier investigate outrageous reports and also make new codes for all of the communication devices at the ranger camps.
Return to Sender: If the player speaks to her, she expresses concern about radio security. She asks the player to visit the six Ranger stations scattered throughout the Wasteland and give them updated radio security codes.
"I handle communications for Camp Forlorn Hope, compiling reports I've received from the Rangers at Camp Golf as well as the brass at McCarran."
"I have the delightful task of tabulating stockpiles, kill ratios, mission success rates, radiation deaths, and other truly fascinating numbers."
"We've received some disturbing reports from some of the Ranger stations - heavy casualties at Alpha, Super Mutant Legionaries at Delta. The weirdest one has to be the Great Khans and their trained Deathclaws at Foxtrot. These reports can't be accurate. Can they?"
A number of interactions between the player and Reyes were cut prior to the release of the game. Of the more interesting options which were cut, a partially removed dialogue option exists where the Courier can tell Reyes "But I already got a tattoo with your name on it. Want to see it?" The circumstances which would have led to the Courier saying this to Reyes are not explained.
Reyes is also an alcoholic, and is, as a result, not taken very seriously by the officers or troopers in the camp.