Xana makes a point of going around Sschindylryn and the refugee camps, asking about possible patrols out in the mushroom forest but a few cycles ago. Attacking a group of surfacers travelling to the trade city of Sschindylryn, they then started to fire off spells at herself. Whether from heat of the battle or if this was a group of heathen Drow, is unknown.
Xana makes it clear Sschindylryn is a trade city, and whether the regional camps around like it or not, it thrives on trade with the surface, and groups travelling there from the surface are important to it's survival. Marking groups and escorting them to the portal is not only preferrable for the city, it also minimises on losses, as a large part of the group attacking the surfacers was killed. Whether she says these things because of her houses links with the city or if other Drow see this actually makes sense is another matter entirely.
((Aware the Drow were DM spawned, but incase this kind of encounter happens it's good to hear peoples opinions))