Well, children, now you've done it.
3 seconds sound clip from the The Secret of NIMH (1982) movie soundboard.
You can hear this line at 00:17:34.303 in the Blu-ray version of the movie.
Quote context
[...]
- I have just one thing to say: that child is a brat.
- I came here to inform you that the frost is off the ground and moving day is at hand.
- Prepare to move your very, very odd family. Good day.
- You never know what might be lurking about out there, what with rats in the field.
- Well, children, now you've done it.
- The Shrew means well. She only wants to help.
- Dream by night, wish by day, love begins this way.
[...]