My first thought is she would appear in Doctor Strange in the Multiverse of Madness
But I feel like she should appear in Doctor Strange 3
Since Clea took Doctor Strange to the Dark Dimension, I feel that we could see her again
My thought is that both Nico and Karolina will join Doctor Strange and Clea on their adventure in Doctor Strange 3
Since season 3 of Runaways had Nico trapped in the Dark Dimension for a while, I feel like she could come back
In addition I think Morgan le Fay should also return since she also came from the Dark Dimension
I think this would be the best way to have Runaways tie into the MCU movies