as a closing SSV who was a primary closing barista and trained a lot of green beans to close, I have to echo this sentiment. open/close have specific tasks and routines (as you know), which can be a lot especially for newer hires that are still getting the hang of “regular” (mid) shifts. the SSV may not be able to provide adequate support/guidance if she’s never opened; even if you give her a detailed list of tasks, she’ll probably have questions and/or make some mistakes. which is understandable but also avoidable (by scheduling a more experienced opener).

that said, OP, I genuinely applaud the intent behind your offer and how you’re looking out for your coworker! and I agree that your SM calling her out in the group chat is not cool.

maybe see if your SM would be willing to schedule them a “training” open or two with you or another experienced opener to show them the ropes? we’ve done this at my store for closes (I think also for opens but I’m not 100% sure because I don’t open 😅) and it definitely helps in the long run.