Scribe Jameson oversees the archives in the Citadel and is charged with protecting the whole of the Brotherhood's knowledge. More importantly, she keeps the scrolls that record the deeds of all Brotherhood members.
Collecting Holotags: Any Brotherhood of Steel holotags you find can be handed over to her, and she will reward you with 100 caps and 25 experience for each Tag (the xp is affected by Swift Learner, like all XP). She also says she will give something "more interesting" every now and then, mentioning "advanced tech," but she never does.
She also goes into significant detail on the inner workings of the Brotherhood, explaining the different orders, how the chain of command works, etc. Very nice if you're interested in the story of the Brotherhood.
When asked about the Enclave, she says almost nothing, stating they're "not worth discussing" and hoping soon "we won't have to think about them at all."