Am I entitled to order my wife to cut off her audio and visual communication with her sisters via social media, fearing that their husbands may become aware of the content of this communication?

A Muslim's jealousy over his honor and the sacred limits of Allah is a sign of goodness and faith. However, there is praiseworthy jealousy and blameworthy jealousy. Jealousy in the face of suspicion is loved by Allah, while jealousy without suspicion is disliked by Him.

If the wife is upright and there is no suspicion, then do not prevent her from communicating with her sisters. You can advise her to be cautious and not to post her pictures. However, if there is a cause for fear, then you have the right to prevent her, as it is your duty to protect your wife and prevent her from causes of temptation, in accordance with the Almighty's saying: "O you who have believed, protect yourselves and your families from a Fire."