Okay, seriously. Under NO circumstances, should you actually consider giggling when you’re trying to get your baby to go back to sleep. You won’t be able to contain yourself. You will wake the baby up, if only briefly.
It is rather difficult, though, when you put your hand on your baby’s head, and stroke her down her nose, between her eyes, and put her to sleep just like you can a puppy, to not giggle about it.