My other kids all did this as well and they never took a bottle. From birth to 14 months or so I was up 6-12 times a night because they needed to eat. I nearly went insane with sleep deprivation with each of them. They are all very thin with very high metabolisms so I have no doubt they really needed the calories. I guess my body just doesn't make much milk in the evenings and at night.
I'm glad my baby is full and happy. I used to e so anti formula. I thought of it as, at worst, poison at best medication to be used only when necessary. I guess that's how I'm using it, as medication. It's for my mental health and her physical and mental wellbeing. I've battles severe post partum depression with each child and I'm sure it had a lot to do with how exhausted I was. Will never judge a mom for formula use ever again.