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It's hard to believe Beyoncè gave birth to daughter Blue Ivy just over two months ago.

The "Single Ladies" singer stepped out in New York City last night in a curve-hugging, navy dress to show her support for Michelle Obama's star-studded fundraiser for her husband's re-election. The Grammy-winner attended the event with her mother, Tina Knowles and hubby Jay-Z's mother, Gloria Carter. Beyoncè was swarmed by paparazzi, all hoping to get a shot of the sexy songstress's post-baby body, as she left the event.

The new mom looks like she's back in her pre-baby shape, perhaps thanks to concert preparations. Beyoncè announced on her website yesterday that she'll return to the stage Memorial Day weekend to perform three shows at the Revel Resort in Atlantic City, N.J. The performances will be part of the opening for the boardwalk resort. Tickets go on sale April 6.