"--fe -s - --t ---e ----. -t's best when y-- ---r---se."
~Ge-rge Gershw-n

That's an apostrophe in the fifth from the last word.

Letters to guess:

AB IJKLM OPQ UVWX Z


Karen: 3 T's = 3 plus 1 Y = 1 = 4 plus 1 F = 4
Felicia's Mom: 2 N's = 2 plus 2 H's = 2 = 4
Catty1: 8 E's x2 = 16 plus 3 R's = 19 plus 1 B = 20 plus 3 G's = 23
Mr. Spunky's Mom: 4 S's = 4
Asiel: 2 W's = 2

Used letter board: C, D