While dressing like that may keep people from checking her shoes too closely, it would have the disadvantage that every bored security officer would be checking her out on video monitors. She’d have a tough time staying out of surveillance in a building with any security.
Most data centers I’ve worked in have annex staff/operations areas with open and often active network ports. If they don’t have some sort of NAP or NAC product running on their network or are otherwise diligent about turning off network ports at the switch, it would be pretty easy to pull this off without much effort.