Re: Going back to work and not sure what to do...
First, make sure your DD will take a bottle! She may not take one from you, since she knows you have the real thing only millimeters away. So have daddy or grandma offer it, when you are not in the house (if possible).
Second, start pumping ASAP and make sure that you're going to have enough milk for the time you will be away from your baby. That usually means about 1.5 oz per hour of separation. Moms who pump after feedings when they are with their babies may have difficulty yielding that much milk in addition to what their babies take- not saying you will have difficulty, but you should be aware of the possibility!
Breastmilk is good in the fridge for up to a week, so the milk you pump today and tomorrow and Friday does not need to be frozen. Just suggest that grandma uses up the older (Wednesday) milk first.
When you get a freezer stash going, I suggest pumping into a bottle (no liner) and then dipsensing that into storage bags of 2-3 oz apiece. The storage bags can then be poured back into a bottle (no liner necessary, with many brands of bottles!) or sorage bag and fed to the baby.
Again, most babies need only 1.5 oz of milk per hour of separation, so the quanities in each bottle should be small, no more than 2-3 oz. Keeping the bottles small reduces overfeeding and waste. If your baby doesn't finish a bottle, it may be returned to the fridge and the unused portion used at the next feeding.
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!"