How is Jael like Ehud?
Jael is a lone assassin, who accomplishes her ends by deception.
She slays her victim when the two of them are alone in a private chamber.
How is Jael like Shamgar?
She is a makeshift fighter who uses an improvised weapon.
If Shamgar was likely not an Israelite, Jael is certainly not; she is a member of a Kenite splinter group which is at peace with Jabin, Israel's archenemy (Judges 4:11 Judges 4:17)!1
18 And Jael came out to meet Sisera and said to him, “Turn aside, my lord; turn aside to me; do not be afraid.” So he turned aside to her into the tent, and she covered him with a rug.