It would be interesting to know what bus route Eileen normally took, or which one she planned to take that day, and where all the stops were.
Since she was leaving a known place and her destination stop was known, there would have been a finite number of stops in between. Were any of them near the area where she was found? Were any of them near potential places of imprisonment?
I suspect the bus route came out of D.C. on Michigan Ave. and out Queens Chapel Road. Her parents lived in the Castle Manor neighborhood which is close to Queens Chapel Road. The other possibility would have been a bus coming out of D.C. along Rhode Island Ave., which becomes Baltimore Ave. (Rte. 1) in Hyattsville. I don't know what the routes were back then, but today the closest bus to her parents house that comes up Rte. 1 would have let her off several blocks away. Neither route is close to Mt. Olivet Cemetery, which is the neighborhood where her body was found. So it seems she had to be transported some distance from where she was captured.
Lloyd Lee Welch lived on Alt. Rte 1, a little east of Rte. 1. His girlfriend lived to the west in Takoma Park. He probably took the bus between Hyattsville and Takoma Park -- not sure what route, but it would have crossed Queens Chapel Rd.
Regarding Eileen's high school, her family attend St. Jerome's School and from there her brothers likely attended DeMatha while she and her sisters might have attended Seton in Bladensburg or Regina (now closed) in Adelphi.