NOTE: This mob is transient and will appear in random zones. For our purposes, she's listed in North Ro because she has to go "somewhere" and the North Ro zone listing just happened to be that place.
Marcia Attamilgad is an adventure merchant who only deals with the Noble currency. She will spawn in one of a number of possible zones (see below) with a single rare item for sale at approximately 00:00 PDT each day (her location and loot table do not appear to be affected by server restarts).
If her inventory has been sold out for the day she will tell you 'I'm sorry, I don't have any items that you can use at this time. Come back and see me again once you become more accomplished.'
For information about locating her at any given time or to see what she won't buy, see this quest entry.
Here are her possible locations:
Butcherblock Mountains: at the Wayfarers camp.
Commonlands: at the Wayfarers camp.
Everfrost Peaks: at the Wayfarers camp.
Mountains of Rathe: south at the Gypsy camp at /loc -475, +660
North Karana: -629, -123, -7 at the gypsy camp mid zone.
North Ro: at the Wayfarers camp.
South Ro: +4737, -1902 at the gypsy camp near North Ro.
Toxxulia Forest: +1463, -1193 close to the Erudin PoK stone.