Watching a documentary on the juvenile correction facilities in Indiana, for kids who have committed serious crimes, and this quote jumped out at me:
"We know their brains aren’t full developed, not until they are 23, 24 are their brains fully developed. Sometimes in talking to the students you realise, they hadn’t thought it through. It seemed like an idea, it didn’t seem real, They thought it was going to turn out somehow differently." -Lori Harshbarger, superintendent of Logansport Juvenile Correction facility
Sounds very much like the mindset of Beth in Coda. And again backs up all the evidence that an 18 year old is NOT a full developed “woman”. She is a girl, who acts impulsive and makes mistakes.