Eva Braun was Hitler's consort and lover. They were not wed until shortly before their suicide in the Fuhrerbunker under the Reich Chanellery (at least according to History).
During Hitler's defeat at the hands of B.J. Blazkowicz in Wolfenstein: 3D , Hitler calls out to his dear Eva.
The name of the submarine in Wolfenstein: The New Order is Eva's Hammer.
It is unknown what ultimately became of her since Adolf Hitler's assassination at the hands of B.J Blaskowicz, but it is possible that she committed suicide by cyanide pill, in accordance to Hitler's last will and testament, which states that in the event of his demise, Braun was to take her own life by ingesting the cyanide tablet provided to her, after which the Nazis would then disavow All knowledge of Braun‘s involvement with the Third Reich, which may explain why she was never referenced during the events of Wolfenstein: Youngblood.