Animal Kingdom has quickly become one of my fave resorts, even if the DVC rooms desperately need a refurb. I really like staying there for a more relaxing vacation. And honestly, the bus service is not bad at all. I timed the buses and you can get to Epcot in like 10min. Magic Kingdom was the farthest, closer to 20min. It's also pretty close to Disney Springs as well. The Victoria Falls Lounge is really nice as well.
But, if you know you're going to be spending a lot of time at Epcot, choosing BC might be better since you can walk to Epcot from there and would have easy access to the Skyliner. You can also walk over to the Boardwalk and hit up Abracadabar.
Unless I was planning on spending a lot of time at the resort, I would pick BC for a girls' trip.