Casting Betsy is difficult for me because *I* need to pair her with an actor for Brian. In my head, they’d be his & hers SHIELD agents, like if both were Bond, but Brian went MacGuyver and Betsy went Widow.
Betsy finds an artifact during a mission and brings it back to HQ.
Brian analyzes it, makes progress without knowing it, gets drunk crashes his motorbike and has a Captain Britain vision. Chooses Amulet. Adventures ensue. Eventually Betsy catches the artifact, has her own vision, chooses Sword... and both twins defeat The Fury.