Just this: No one, not even the Prince, knows who that girl is.
7 seconds sound clip from the Cinderella (1950) movie soundboard.
You can hear this line at 01:01:46 in the Blu-ray version of the movie.
Quote context
[...]
- You clumsy little fool. Clean that up then help my daughters dress.
- If he's in love with that girl, why should we even bother?
- Now, you two, listen to me. There is still a chance that one of you can get it.
- Why, Mother, what do you mean?
- Just this: No one, not even the Prince, knows who that girl is.
- We know! We know! Cinderelly!
- Cinderella, get my things together.
[...]