Reference for Ketubot 193:9

ודלמא עצה טובה קא משמע לן דלא ליקרו לה הדרינתא א"כ ליתני גובה כתובתה מן השאר מאי סמך לה שמע מינה שיירא אין לא שיירא לא

But perhaps this is only good advice, in order that people might not call her “one who goes back and collects twice”? If so, he should have stated, “She collects her ketubah from the remainder.” Why [then did it teach] “This is a support to her”? Thus learn from this that if she left property [for her ketubah] she may collect, if she did not leave, she may not.

Jastrow