“Sisera fled away on foot to the tent of Jael the wife of Heber.” It is noteworthy that Sisera’s army fled west toward home, but Sisera fled east, in the opposite direction of his army. The fact that he fled “to the tent...of Heber” meant he knew Heber was there and was intending to hide there.
“To the tent of Jael.” It is possible, even likely, that Heber had more than one wife, each of whom, according to custom, would have their own tent. For an unstated reason, Sisera went to Jael’s tent. It would have been Heber’s tent, but the tent used by Heber and his wife Jael, and therefore referred to in the text as Jael’s tent.