Rachel is the primary photographer for an artist named Terence Koh, who frequently collaborates with Abramovic. Here, he's in a death pose on a piece of hers: http://purple.fr/diary/terence-kohon-a-work-by-marina-abramovic-at-a-collectors-house-east/ Another photo of the same set: http://purple.fr/diary/terence-kohon-a-work-by-marina-abramovic-at-the-collectors-house-east/

A video from a MoMA party: https://www.youtube.com/watch?v=zPPKj99ZV60YouTubeYouTube List of attendees: "Those in attendance included Madonna, Mary-Kate Olsen, Yoko Ono, James Franco, Lou Reed, Patti Smith, Chloe Sevigny, Penn Badgely, Padma Lakshmi, Rose Byrne, Kim Cattrall, Lucy Liu, Marina Abramovic, Daphne Guinness, Terence Koh, Andrej Pejic, Leelee Sobieski, Cindy Sherman, Agnes Gund, Katharina Sieverding, Rachel Chandler, Michelle Harper, David Rockefeller, Jr., MoMA's Director Glenn Lowry, Volkswagen's Martin Winterkorn, and Director of MoMA PS1 and MoMA's Chief Curator at Large Klaus Biesenbach."

Rachel was a photographer/attendee at Marina Abramovic's 2010 "The Artist is Present" performance at the MoMA http://www.patrickmcmullan.com/site/event_detail.aspx?eid=32454 (look for her name on the left-hand list of Featured People and use the filter function)

This is the one I think you might find the most interesting, and I'm surprised this hasn't been delved into before. Abramovic gave a very controversial performance at the LA MoCA that involved a kind of pseudo/ritualized cannibalism of a female body, and Rachel was present as well. https://www.artforum.com/diary/id=29517