Not believable. If she only had one beer, drunk guys would not have been able to force her in the room. If she had been able to kick and scream, she would not have been vulnerable.
That's the thing about predators at any age. Their prey is women who they perceive as vulnerable.
She has apparently admitted to being an alcoholic during that time. The words “one beer” confirm it for me. I drank in high school and never worried about counting my drinks at parties.