Hi Amanda, so good to hear that things are going so well.
I'd play it by ear, she is probably too small now to go through the night regularly without a night feeding but every once in a while little babies may just be giving you a break. Bear in mind that she's probably coming up to a growth spurt fairly soon and she'll likely be on you like a leech [:0].
One of the things about BF, it's a more dynamic relationship than with FF. This just makes sense, the formula recipe is static, while the content of BM changes over time. The upshot of this is that I think it takes BF babies longer to get into a very established routine and then they break out of it more easily. It's very handy when you are out and about, if they get hungry when you don't expect it... well you're all ready to go. On the other hand, with growth spurts for example, you have to deal with maybe hourly nursing for a couple of days rather than being able to just give more at a feeding.
I'm curious as to why your ped would recommend the top up bottle. I don't know of anybody whose supply didn't drop off in the evening..... and then pick right up overnight. The biology of that explains the night sweats and all those uglies. However, volume issue aside, the evenings BM is just as nutritionally statisfying. Some babies are what are called cluster feeders. Lucy and Chloe both were. They would go a long time during the day between feeds 3-4 hours but in the evening from say 7-9 pm, they'd be on and off the breast like yo-yos. Then they'd settle down and sleep until 1 am, wake, nurse and then sleep until around 4. It wasn't purely hunger that would keep them feeding.... it was the contact and interaction component too. Finn, on the other hand.... every two hours non-negotiable. I used to say in the ugly blur of the first three months that I could remember distinctly the last time I'd had more than two hours of consecutive sleep..... the night before my water broke!!! He kept that up for his first nine weeks, then one day... he went to every 4 hours. Literally overnight and I was so engorged and pumped so much that there wasn't room in the freezer to deal with it all!! I tend to go by size rather than age when trying to figure out when they're old enough to go through the night by themselves.... because they have a big enough stomach to hold enough. 13-15 llbs is my personal rule of thumb. Sadly, mine are such skinny minis that means 6-8 months of night feeding.
As for the co-sleeping.... pace yourself. I think that for exclusively BF, some form of the practice is what evolves..... you're too tired to deal otherwise. There are things you can do that can make it as safe as possible but if you never get comfortable with it, that's fine too. This is one area where your expectations and what ultimately turns out to meet your needs sort of have to be worked through.
Mom to Finn, Lucy (preeclampsia and HELLP) and Chloe.
Moderator HELLP Syndrome Survivors