I'm just wondering if the girl wanted to be married...Nothing in the article states that the girl did or didn't want to be married.
Since the sex was apparently consensual, I'd say the odds are that the girl thought she was in love with the guy.
Whether or not she will maintain that feeling over years of marriage is another story. On an anectdotal level, I know of one couple that had to get married in my high school as freshmen have had a great marriage for more than fifty years. They will tell you today that they were more determined to make a go of it because of all the naysayers who said it would never last.
Nothing at all, except that she married the guy.