Well, it's very obvious she's set her cap for him.
5 seconds sound clip from the Little Women (1950) classic radio play.
You can hear this line at 00:23:34 in the radio play.
Quote context
[...]
- And please tell your mother that I think all her daughters are simply fastidious.
- Oh, Beth! Isn't he just perfectionary?
- Somebody's coming. Let's hide again.
- Oh, it's that stuck-up Mrs. Gardiner and her daughter. Don't move.
- Did you see him, Sallie? Theodore Laurence still with that impudent Josephine March?
- Well, it's very obvious she's set her cap for him.
- Well, Mr. Laurence will have something to say about that. I'm sure he has other ideas for the boy.
- Of course, it would be a triumph for Mrs. March. I must say, she's managing the affair very well.
- Amy? Amy, did you hear what they...? Oh, Amy!
- Now, this is the third dance, Jo, and I'm hanged if I'll let you refuse me again.
[...]