Kate has been ignoring Jo's capabilities and testing Jo's patience by making her work very hard without showing much appreciation. At the same time, Kate is worried that Jo will override her authority, and frequently stops her from having direct contact with customers, even simple chat.
Jo has been suffering and has started to avoid bad feelings by not having much eye contact with Kate, while still working hard. Kate never even gives a nod or smile to Jo when they meet in the staff room. Other colleagues know the story and feel sorry for Jo, but are not able to offer any help to her.
(The above writing describes the true situation, and is written by myself. I need suggestions to make it better.)
Her colleagues would be sympathetic to her situation.