Evie Frye is the first playable female lead in a main Assassin's Creed series entry.
Evie is one of the two protagonists of Assassin's Creed Syndicate, alongside her twin brother Jacob Frye. The game is set in Victorian London, and players can switch between the siblings during much of the campaign. Evie specializes in stealth and investigation, while Jacob more often emphasizes direct combat.
Earlier Assassin's Creed games had important playable women. Aveline de Grandpré starred in Assassin's Creed III: Liberation, a separate spin-off, and Aya is playable in portions of Assassin's Creed Origins. Those examples can make the wording easy to misread.
Evie is the first woman to share the protagonist role in a main numbered-style console entry of the series. Syndicate's dual-protagonist structure means she is not the only lead, but she is the first female lead in that main-series context.