In which Matthew Crawley falls for the American niece of Robert, Isabelle "Belle" Levinson who is living at Downton with her family after her mother and father died in a mysterious fire. But will Belle feel the same for the heir of Downton. Matthew Crawley x Belle Levinson (oc) Season 1-season 6. Will Belle's older cousin Mary accept? Disclaimer: I don't own Downton Abbey just my OC's.