Depending on how many hours you work, you may not need to mess with bottles at all. Does she take a sippy cup at all? There are some soft spouted sippies you could experiment with, with ebm to start. Both my babies skipped bottles and just went straight to sippy cups.
Or, do you have the option of taking your lunch break to go nurse her? She should get to a point, around 9-10 months, when she is only nursing/milk feeding 3 or 4 times per day. Then it gets very easy to let someone else care for them for day times.
If she is taking solids, you can also try to work her into a schedule where she takes her solid meals during the day and your absence, and nurses more at night when she is with you. For example, you could nurse her in the am, she could eat breakfast and lunch at day care solids, and then nurse her right when you pick her up, again for dinner, again at bedtime, and maybe once in the night.
It just depends on what you want to do, just know that you don't *have* to wean your baby to formula. Pumping is an option if she doesn't take to formula, or if you just decide to skip it all together.