It could be passing phrase for your girl. If she can sleep through, let her be. I feed almost hourly during my gal growth spurt ( sorry, maybe wrongly spelt)
As for poo, as long it dont come out hard like bullet then she is not constipating. I got the same concern and my pediatrician just merely told me the baby is having fun keeping the poo in her (faintz). But if you are worry, check with your pediatrician. Or you can try tummy exercise, it help.
I remove dairy product from my diet as it cause tummy wind in me which also result in my baby too. I notice when my tummy is unwell so is my baby.
Try not to overfeed.
Baby pattern change every now and then, dont worry, just watch out for the change and make adjustment according. They are their own boss.