afraid of (one's) own shadow

Translations
бояться собственной тени
She is so timid, she is afraid of her own shadow.
Она такая застенчивая, что боится собственной тени.
Definitions
To be excessively fearful or anxious, often to the point of being overly cautious or paranoid about minor threats or situations.
Words
shadow

noun
тень
afraid

adjective
испуганный
own

adjective
собственный