Very difficult without knowing every single little fact, such as:
did they know each other, were they dating?
where did the assault happen?
who did the victim tell, and why?
To put it bluntly, the victim will be less likely to be believed if she was caught in a undressed in her bedroom with the boy and they had been dating for a while than if he were a total stranger who accosted her in a public place.
In the first scenario the defence would say that the victim consented, is 'crying' rape and attempted suicide because she was caught out, her parents are angry and she is ashamed and frightened of the repercussions.