The nearest hotels to St. Joe's are about a half mile north of St. Joe's University on City Line Avenue. There is a Hilton, a Crowne Plaza, and an Adams Mark. All are within about a mile of one another, with the Hilton being the closest to St. Joe's. All the communities on the west side of City Line Avenue (across the street from the Hilton) are very nice residential areas that I ran in for years and you can't go wrong. The streets, however, are not squared off, so if you don't have a GPS to get you back to your starting point, it is not difficult to get a bit lost the first time you run them.
If you want a pleasant route into the surrounding communities and you are staying at the Hilton, head down Old Lancaster Avenue, which is right across City Line, until you reach Montgomery Avenue. Turn left on Montgomery and you can run for miles on that street. There are really nice roads that branch off Montgomery (with some good hills in places, but most have no sidewalks so you're truly on the road)that are very peaceful and make for beautiful long runs, especially on a weekend, but again, easy to get lost on without a GPS.
There are many beautiful places to run in Philadelphia near St. Joe's once you know the area. Someone mentioned Forbidden Drive in Fairmount Park, which is an amazing trail run within the City and truly beautiful, as is much of Fairmount Park. Fairmount is close to St. Joe's. The River Drives in Fairmount are fine to run on and you will usually see many runners out, but I wouldn't venture off them-some of the surrounding areas are not great for a solo runner.