Fayes is a real estate agent. She finally rented their old house, which they still owe for. Ender asked Rein, "how come Nina's parents are buying a second house now and have no debt, while we still owe... how much?" "400K$, and don't look at me, I was in the Navy - ask your mom, she was running the show while I was away".
"All my friends said it's a great thing, loan where you pay interest only... and I listened to them! How could I have been so stupid?"
Feels like some satisfaction. Don't even need to ask for a chance to say "I told you so".