I work from home, but with my first son I went to the office two days a week while DS was with my husband. So I hope I have some helpful advice :-)
Working from home is harder than I thought it would be. Obviously there are all the things around the house that need done as well as a baby that needs tended to, so it's hard to be able to sit down and focus on work. It's much easier to be in an office! I'm not trying to dissuade your choice to work from home- not at all, I'm glad I am able to do it- but just a warning that it *seems* like it will be easier but it's much much harder. I think the general population thinks I have it so easy working from home. That is not the case AT ALL.
Pumping at work- try to pump only when you feel like you'll get a good amount of milk, either when baby would normally feed OR when your breasts feel full (can you feel your milk come in? You may have never felt that sensation before, but you may start to when you are away from baby). I didn't pump as often as I would have nursed- I would pump maybe just once a day during a 6-8 hour stretch, and I pumped/fed baby before I left and fed him again right when I got home. I never had supply issues because I was only gone those two days and baby would nurse all the time when I was home, so my body never decreased my supply. But if you just pump the one or two times, you are more likely to get a huge amount of milk because you're so full. If you try to pump really often you might only get a bit each time and it would be really discouraging. Waiting until I *knew* my breasts were full of milk made me really confident that I'd get a ton of milk- lactating has such a huge mind/body connection, you know? I also find that having a distraction helps when I pump. I literally surf the web when I am pumping and all of a sudden I'll look down and have two completely full bottles of milk in less than ten minutes, whereas if I am just sitting paying attention to the pump I'll get less than half that amount in 20-30 minutes. Find what works for you! Dont' stress- stress will inhibit your letdown. If you're in a place where you can't *do* something else, at least think about something else. Make a grocery list in your head, for instance. Something to take your mind off the pumping and the thought of "needing to get milk".
I don't think she'll freak out. If you are not around, she will be distracted and bonding with daddy. I was always surprised that my older son would eat SO much less when I wasn't home- but it was because he couldn't see/smell the milk machine :-) He was very happy being home with DH. On the other hand, I know some babies eat MORE because they miss mama. So be prepared for either. I've found that I always *think* my babies will freak out when I am not there, but they do SO well. It surprises me. Be ready to give extra cuddles and attention when you get home and even that night. Some babies make up for lack of mama time by waking up more at night. My DS was a terrible sleeper the nights *before* I went to work. It sucked because that is when I most needed sleep! But I think his body knew our routine, and knew when I would go to work. Just remember- in psych terms a "healthy attachment" means that baby might be sad when you leave (mine was) but recovers quickly and is generally fine while you are away. That means they are trusting of their environment and are developing self-confidence. It's a good thing! (I would be a little hurt when DH would tell me that DS didn't seem to miss me after the initial crying spell when I left. But it's really a sign of good attachment).
As for them working out their own routine- yes. It's hard to let that happen though, because as the mama we know best, right?!! But trust that your DH and baby will work it out. DH does things different from me, but that is okay! Our sons are learning that mom and dad are different- I am more nurturing and, well, uptight haha. DH is more carefree and fun with the boys, and when they need comfort, DH is more of a strong support than a tender comforter. That's normal! :-)
Be thankful for that bf-ing relationship. It is a beautiful thing and will continue to bond you and be an integral part of you and your DD's relationship for a long time to come. It will be the thing that reconnects you when you return home from work.