Have you tried a few different teats to see if it's a texture or shape that she is objecting to?
You could also try a sippy cup that doesn't have the spill proof valve so that you can just tip it in.

Is it just you trying or have you left her alone with someone else to try? She could be holding out for you but could drink if you're not about. The little monkeys know you have the boobies!

Caleb flat out refused to take a bottle or a dummy and has only now started to drink from a sippy cup. I couldn't even get it in his mouth.

I've left Caleb with an expressed bottle and he's not touched it at all and he's been fine. He attacked me for a drink when I got home though If she has her morning feed and then one when you come home at 4 then she's really only missing one if she's on 4 hourly b/f IYKWIM. It's not ideal but it's not the end of the world and it is only for one day a week. If it was every day I'd be more worried.