Anna:
Just for your information, there is also a public transportation alternative: A PATCO speedline train runs every 20 minutes on Sunday into downtown Philly from Lindenwold (which is on U.S. Route 30, southeast of Cherry Hill) <
http://www.ridepatco.org/map_nj.html>...perhaps Cristina could drop you off there, since if she's heading for the airport she'll probably want to use the Walt Whitman bridge, and won't come too close to Penn.
The train ride is under 30 minutes to Market Street in Center City. From there you transfer to the westbound SEPTA Market St subway <
http://www.septa.com/maps/market_frankford.html> which will take you directly into the Penn campus and University City.