Four Years.

It's been four years since she saw you last. The last time she saw you, you shoved her out of the way when the Cart Titan barreled through to get Reiner. One moment you were there. The next? Gone.

She thought you were dead. Shiganshina killed nearly everyone, and she just had to own up to that, especially as the new Commander. Until after Liberio, where you were extracted with Eren, and the scouts discovered you were kept as a prisoner in Marley for four years in a cell.