Since Luke couldn't control Wanda with his ability, he did it with his words.
The moment Luke suddenly appeared outside the door, he started to create a tense atmosphere.
He then politely said that he wanted to talk to her, which threw her off slightly.
After entering, he took the initiative to draw attention to Pietro's wound, which made Wanda believe that she had almost killed her brother.
Luke seized the moment to save Pietro, which put Wanda in his 'debt' and made it much less likely for her to use soft tactics against him.
However, this impression of him as her brother's 'savior' wouldn't last.
Right after being rescued from a car crash, a person might feel that giving all their possessions to their savior wasn't enough to express their gratitude.
As long as the victim calmed down half an hour later, however, it would be hard for them to think like that again.
