I can't imagine that ANYONE in the world doesn't know how popular the movie 'Frozen' is amongst all girls. I have boys, we hadn't noticed it, moved in opposite a girl; BAM! Frozen everywhere.
I have a work colleague who had seen the crochet mermaid hair I'd made, she has a little girl who is in to? BAM! Frozen. She's been looking for Elsa hair for ages, can't find any and asked if I could make something up in time for a birthday.
I'll get the pattern on Etsy as soon as possible for Crochet Elsa from Frozen Hair (snappy).