Well, I once thought that "if the baby is hungry enough, she'll take anything eventually."
However, I babysat for a friend and her little darling simply didn't eat all day, or ate very little, then he would nurse like crazy when she got home from work. After the initial shock and worry, it became his pattern, and her milk supply adjusted accordingly. She still pumped at least once during the day to maintain her supply and have milk to leave with me. Eventually the baby would take a couple ounces in the morning, then a couple more in the afternoon. He took two very long naps during the day too, so maybe that's why he could hold out for so long -- his body literally went into "energy conservation mode" :-). He was nearly a year old before a took a bottle well.
Also, I thought this little guy's experience was out of the ordinary, but I have three other friends since then whose babies did the same thing!
So, if you can, as you prepare to go back to work, offer a bottle at the same time every day just for the routine of it. And yes, it will help if someone else offers it. Also, you may not even be able to be in the same room, or even in the house. If she knows there's an alternative, she'll wait for it. Maybe your husband could have bottle duty while you take a walk around the block.
However, if it's a source of stress and freaking out, forget it. Just prepare the childcare provider in advance that feeding time could be a challenge. Babies adjust pretty quickly to new routines and environments. Hopefully they'll get the kinks worked out in her first week while you're back at work.