It may also be worth adding in an extra "feed" at the moment - where you feed the freezer rather than the bub.
I found that when I returned to work my DS (10 months at the time) would only actually take 1 bottle of EBM a day, and some on his cereal - and then have one heck of a feeding frenzy when I got home!
Miss E will work it out - and she will probably have very different feeding patterns when you are and aren't home.
good luck!