Chris Avellone, who designed her, described Xian as "a cute Chinese descendent scientist in Dome", and nobody else ever mentioned her. There is no design document for her. The Boulder doc says about her personally:
Curious, logical. Grew up in San Francisco among the Shi. Moved to NCR as part of an exchange program. Biology, doctor, outdoorsman. Doesn't smile much. Will be interested in the PC if he's charismatic and/or smart. [ ] Can do Science for the PC. Skilled enough to make bullets and gunpowder.
It cannot be said for certain that the above concept art, labelled only "Boulder scientist/hottie" refers to her, but it is highly probable.
Note: At the time Van Buren was cancelled, Xian obviously was no longer supposed to be a companion NPC. She is not listed as such in the Boulder design doc.