Jennifer Love Hewitt was never on Supernatural. Haha.
But as far as the brother bickering goes, the second half of season 9, right after you stopped, is probably the worst in the series.
It gets better in season 10 but the writers finally dropped it all together after that. Seasons 11 and 12 had them fully working together without the forced arguments.
Who am i thinking of? She was the that season's big bad