Have they considered living in DC close to work rather than in VA?
There are some great neighborhoods close to foggy bottom and brookings that many 20 somethings would really enjoy. They could probably find a place where both could walk or take a short metro ride to work.
That whole area is safe, walkable, vibrant. Rock Creek park trails are close by. It is urban but not skyscraper and all concrete urban.
They could also consider leasing for a year while exploring the area.