What helped y’all improve when you were new?

I’m an ssv and my store has a new hire she’s never worked a job before she’s been at the store for a couple months now I’ve given her a lot of practice on bar at least an hour and a half with me or a trainer and she still can’t make an iced latte no matter how much practice she gets she never retains any knowledge anyone have any tips on how to get her to improve?