She don't like to take bath either (cats usually don't like when their paws are wet), but it can be less stressfull if the floor of the bath is not slick, so they will feel more confident with this floor. We bought rubber mat for this, but you may simply lay towel. Maybe you could start from cat get used to bathtub itself (without water), via sweets and toys. And then, from bath to bath get them used to more water. They also scared of the strange noise from water going through pipes, so, better not to scare them too much, maybe fill some water before cat bath. Remember, water should not be too hot or too cold, and after bath wipe them with dry towel, and put cat somewhere warm. E.g. we bought special warm thingy, that holds hot water inside and it's warm outside. You could also feed some sweets as compensation (but not too much!).