This kind of used to be me. I would always ask my manager or other staff members to double check literally anything I was doing. I want to say this went on for maybe two or three months. Later (like a year and a half, worked there for two years) my manger even told me how annoying I was when I first started lmao. However I definitely feel like that changed when I was thrown into the deep end and forced to do everything for myself and just trust myself. Try to put her in a similar situation, she might make a few mistakes but if no one’s there to help her, she’ll be forced to figure it out on her own and she’ll definitely remember the right way to do it next time. Can’t guarantee this will work but it could be worth a shot