You might hear: "Just five more minutes," "I am not tired," "I need to tell you something," and then another something, and another. Elementary-age stalling is often partly genuine (the brain is still active), partly relational (they want more connection), and partly habitual (stalling has worked before). All three are worth understanding before responding to any one of them.
You have time for one more thing before lights out. What do you want it to be?