What's the meaning of 'turn me in'?
SCRIPT
Gabrielle sees police cars pull up in front of the house, lights flashing.

She gasps.

Gabrielle (quietly): "She turned me in."

She rushes back to her husband and falls on her knees in front of him.

QUESTION
Gabrielle's extramarital activites has been turned out by Helen (a neighbor), except her husband.
Now, however, Gabrielle was panicked by the very situation she's seeing.
I just googled a meaning of 'turn me in' and the online slang dictionary says it means 'go to bed.'
However, I just think it means 'being screwed up by someone', at least this context.
What would you say? Thanks in advance :D

Question

What's the meaning of 'turn me in'?
SCRIPT
Gabrielle sees police cars pull up in front of the house, lights flashing.

She gasps.

Gabrielle (quietly): "She turned me in."

She rushes back to her husband and falls on her knees in front of him.

QUESTION
Gabrielle's extramarital activites has been turned out by Helen (a neighbor), except her husband.
Now, however, Gabrielle was panicked by the very situation she's seeing. 
I just googled a meaning of 'turn me in' and the online slang dictionary says it means 'go to bed.'
However, I just think it means 'being screwed up by someone', at least this context.
What would you say? Thanks in advance :D

Answer

"To turn someone in" means to inform the police about a crime they have committed.
"To turn in"  means to go to bed. For example "I am going to turn in now" means I am going to bed now.
Hope this helps :-)

Answer

To "turn someone in" means to report them to the authorities.  It means someone has knowledge of a crime or breach of conduct and they break their silence and report it.

To be "screwed by someone" acually can be considered true if they turn you in.  "She screwed me by reporting that to my boss!"

Answer

It's basically saying that someone snitched or told the police or another member of authority about a crime that was witnessed or that they saw their friend doing.

Answer

It means that the authorities (police) have been told about something the person did that was illegal.  He will likely be jailed for some time if he has not already been.