So, she might have dropped/lost the purse at Lannigan Field before she headed further away from the arena on Copeley Bridge (depending on which way she was going on the bridge), or it could have been later if she returned to the lot.
On another poster's point, Copeley Bridge is over railroad tracks, not water.
I'm not particularly good with pinpointing on maps, but from the Arena to UHall is a couple hundred yards (at most) south, from there to Lannigan is a couple hundred more west (depending on where in the parking lot...if back by the baseball field, it's a bit more), and Copeley Bridge is between UHall and Lannigan, and slightly south of the Lannigan entrance. If M.H. was on Copeley Bridge going south it would be past a student apartment complex and a bank toward a 7-11 and a few other businesses. Turning right at the next intersection would be heading out of town on Ivy Road/250 Business, and there's a Chinese restaurant, then a grocery store, then a small strip shopping center, then not much else (with railroad tracks behind).
Going straight across Ivy road on Copeley would get into faculty and other housing and winding eventually (half a mile?) to central UVA grounds (with the Aquatic and Fitness Center gym where I saw flyers posted and the football stadium).
Turning left from Copeley onto Ivy would take one past a restaurant, the 7-11, a small shopping complex (camera store and a bank?), a UVA parking structure (set back from the road), and then a motel caddy-corner to main UVA grounds. Turning back north on Emmet Street one would go past UHall and get back to the Arena, circumventing a large block. Continuing east on Ivy Road/250 Business/Main Street (crossing Emmet) would be heading into town and would get one to "the Corner," the center of bar/restaurant activity nearest UVA grounds (and close to the Rotunda and the Academical Village) in about 4 blocks, passing a gas station, tennis courts, a practice/intramural field, the president's house, frats and sororities, the Rotunda, an Episcopal church, a bank, a bagel place, and another convenience store. I wasn't out that night, but it's oftentimes very busy there with pedestrian and vehicular traffic.
But if she was spotted on Copeley Bridge heading north (i.e., toward the arena or back to Lannigan Field), then the above is probably irrelevant.