So Weird (1999)

S3E16 Pen Pal

Molly and Annie's world gets turned upside down when they receive a postcard from an alternate version of Annie, a rebellious punk girl born from one of her divergent decisions. When this alternate Annie unexpectedly appears at her doorstep, Annie faces a pressing dilemma: she must quickly figure out how to deal with this surprising visitor, as they discover that only one of them can continue to exist in their reality.