Becky's marriage and the fallout
I blame her parents for a few reasons. Sure, they liked Becky's good grades and kind of encouraged that, but they never helped her get ready for the future. If they couldn't help with college they should have encouraged her to plan a different route. They just never really even talked about her future after high school.
As it is, I see her logic in eloping. Why stay in Lanford? She moved to a place with more opportunities with someone that she loved. She was young to get married for sure, but I don't blame her for not wanting to move to a strange city for a guy without the commitiment of marriage.
What was her other option? A dead end job in Lanford without her boyfriend? Maybe if she's lucky she eventually puts enough aside for some community college, which she could do and do better in Minneapolis?