What is the effect of seeing the thing on the bed on Maria?

The effect of seeing the clone on the bed caused Maria to pull away from Matt.... to be repulsed.

Matt became aware that María no longer held his hand. She’d shrunk against Tom, and he had his arm around her. The creature—clone—had regained its energy and was screaming again.

“Take me out of here,” she moaned with her face buried in Tom’s shirt.
“I’m not like that thing!” shouted Matt.
“Use your eyes!”
He tried to pull her from Tom, and she shrieked, “Don’t touch me! I don’t want to think about it!”