Complex sentence: Meredith Vickers (Charlize Theron), an upper-level employee of the Weyland Corporation, is Peter Weyland's estranged daughter and joins the "Prometheus" expedition as a corporate overseer.
Split into simpler sentences: Meredith Vickers (Charlize Theron) is an upper-level employee of the Weyland Corporation and the estranged daughter of Peter Weyland. Vickers joins the "Prometheus" expedition, serving as a corporate overseer.