a damsel in distress

Examples from literature

One of these damsels spake Swahili, so we managed to exchange compliments. 
Sir Arthur King, said the damsel, that sword is mine, and if ye will give me a gift when I ask it you, ye shall have it. 
So, riding to the knight who held the damsel, he cried out, "Sir knight, lay your hand off that maid, or else ye be but dead." 
Stand up to me then, said the damsel, "if thou have strength to do so!" When the old woman heard this she was sore enraged, and her hair stood on end like that of a hedgehog. 
The service seemed interminable, and all that time the indignant damsel, wedged in between her aunt and the openly exultant enemy of her House, was compelled to endure in silence. 

damsel | American Dictionary

damsel
noun[ C ]
us/ˈdæm·zəl/
literature dated
a young woman who is not married:
The heroine in this movie isn’t like some damsel in distress (= woman needing a man’s help) waiting to be saved.