Orta is searching the Shaperate in Orzammar for traces of her family's ancestry. Her mother believes that her family descends from Kelana Ortan the last surviving member of the extinct House Ortan, and is trying to find the necessary proof in order to regain her noble status and house. However most of the records were lost during the Fourth Blight when Ortan Thaig, House Ortan's home, was overrun by darkspawn.
Orta would like you to look for some documents on your travels in the Deep Roads. By agreeing to her request, the Lost to the Memories quest is activated. Travel in the Deep Roads becomes possible while looking for Branka in the quest A Paragon of Her Kind.
Once you give Orta the documents, found in Ortan Thaig near the spot where you first meet Ruck, she will ask you to find her at the Chamber of the Assembly. There you can speak with Orta again and she will happily say that the Assembly reinstated her noble House and you ask her for a reward. Asking for any money she can spare will get you 5 . Asking her to support either Harrowmont or Bhelen increases that candidate's support amongst the deshyrs. See here for more information. Orta will also state that she plans to start an expedition to Ortan Thaig in order to claim any riches which were left in there.You can speak to Orta again during a subsequent visit to Orzammar after completing A Paragon of Her Kind. Orta's expedition is completed and she will offer an additional 10 . If you leave Orzammar before speaking to Orta in the Assembly chamber, you will only receive this second reward.