Re: Daytime weaning?
I'm also curious about how long the pumped milk was out of your body before you gave it to your baby. Some moms have an issue with excess lipase which can make their pumped milk taste pretty nasty. Scalding the milk inactivates the lipase, so there is a fix for this problem if it is the reason why your baby rejected the pumped milk.
Also, when you offered the bottle, did you try giving the bottle, or did someone else? Some babies won't take a bottle from mom because they know she has the real deal under her shirt.
In your shoes, I would try giving her a sippy with milk or formula in it and seeing if she will take it. If she will not take formula or pumped milk under any circumstances, I would try to nurse her as much as possible during the non-working hours and at night, and maybe consider finding a daycare that is close enough to work that you can slip over for a feeding during the day. Since you're rightly concerned about the caloric content of solids, I would offer only the most nutritious ones. Skip the cereals, and offer fatty but healthy things like whole-milk yogurt and avocado.
I know this must be a difficult situation!
Coolest thing my big girl said recently: "How can you tell the world is moving when you are standing on it?"
Coolest thing my little girl sang recently: "I love dat one-two pupples!"