She means it.
3 seconds sound clip from the Goodfellas movie soundboard.
You can hear this line at 00:46:29 in the Blu-ray version of the movie.
Quote context
[...]
- Angie, stop picking at that thing.
- The red-haired guy, looks like a farmer?
- I can't get through the gate without this guy's hands are all over me.
- So I told him, Keep your fucking hands off me, you son of a bitch, or I'll cut them off.
- You don't know how lucky he is. I just mention this to Vinnie.
- How can you mention it? Vinnie would kill him.
- If I don't, he'll kill the miserable bastard, then Vinnie will be there for life.
- You think you got problems. What about Jeannie's kid?
[...]