If she seems a little scared then it might be a security issue. You could try a couple things here but make sure to do the changes gradually as any change you make can stress the animal even more.

You could add a second hide, fill the tub with crumpled newspaper/paper or add fake plants for cover, or you could put her in a smaller tub.

Other then that, I wouldn't worry too much. Just keep offering once a week (more often then that might stress her out more and make her less likely to eat). She will eat when she is ready!