Shirley not !!!!!!
have a yellow streak down (one's) back To have a tendency to be cowardly or easily frightened. She likes to strut around like she's the boss of the place, but she has a yellow streak down her back if you ever confront her on an issue. He knew what they were doing was wrong, but he has a yellow streak down his back that kept him from intervening.
Have a yellow streak down one's back - Idioms by The Free ...
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