I could do it, but so can you! Here's how: You are really talking about Henry Jackson Duke the younger, who has two wives listed, one of whom is the incorrect Sarah.
Click "Edit" for Henry. On the right hand side are spouse(s), Click "edit marriage to Sarah."
Another page opens. On that page, immediately below "SAVE MARRIAGE CHANGES" is a link for "remove this marriage." Click that link, then select Sarah and delete her.
Voila! She is gone.
