Maris is a thief. A common, low down, swarmy thief. It’s not her fault she’s that way, though. She’s nice, has a sweet personality, and is most likely to talk a person into giving ‘the poor, suffering little me’ their money, due to her limited skills as a pickpoket.
What she is skilled at, however, is very, very strange for a theif. She likes reading, and has collected many old manuscripts, and is sometimes saught out for just knowledge.
A casual remark by one of the party about something met on a previous adventure leads to a summons to and grilling by the Mages' Guild (or equivalent), probably resulting in an expedition back to that area to recover the things for 'study' by the Guild. The party's presence will be 'requested' for this expedition.