Complex sentence: She is the former Director of Market Development and spokesperson for Facebook, and a sister of the company's co-founder and CEO Mark Zuckerberg; prior to working at Facebook, she was a panelist on "Forbes on Fox".
Split into simpler sentences: She is the former Director of Market Development and spokesperson for Facebook, and a sister of the company's co-founder and CEO Mark Zuckerberg. Prior to working at Facebook, she was a panelist on "Forbes on Fox".