The 31-year-old actress left the hotel alone for the event in the back of her chauffeur driven SUV, reported Showbiz spy.
The couple became engaged in November 2011 and were married on September 29, 2012.
Recent reports claimed Hathaway is trying to scale back her A-list lifestyle to be more relatable.
"She's learned the hard way how popular humility can be for an A-lister. Anne has been giving away a lot of her possessionssuch as clothesmostly to her housekeepers, because she wants to live a less materialistic, decadent lifestyle.
"She definitely admits she's been living too high on the hog given these economically tough times for the rest of the country. Giving away some old clothes is not exactly downgrading her lifestyle!," a source said.