Katie Summer's was reborn as Wanda Maximoff in the 138 universe where Agent Barton sacrifices himself instead of Natasha Romanoff. And Wanda defeated Thanos instead of Tony Stark.
The events of the Darkhold never happened. Natasha found her intriguing because she has red chaos magic but doesn't want to use it. Which she had major respect for. Will Natasha's friendly flirting develop into something more for the Scarlet Witch?