Good Night Baby M

As big sister K was getting ready to go to sleep tonight, this is the conversation that followed (our typical bedtime routine for the most part):

Me: Good night K.  Jo tao*.
K: Good night mommy. Jo tao.
M: Good night K. Buenos noches*.
K: Good night daddy. Buenos noches.
[Pause]
K: But I didn't say good night to baby.
Me: Baby is already sleeping.  How about you say good morning to him tomorrow instead?
[Big sister K gives me a sad face.]
Me: Okay.  Come on.
[We go into baby M's room and stand by his crib, where he is sound asleep.]
K: (whispers) Good night baby.
[Big sister K walks back to her room and goes to bed.]

*Translation: "Jo tao" means "good night" in Chinese and "buenos noches" means "good night" in Spanish.