Adding my wife to my Apple One Premier account

Thank you. But that didn't quite answer my question. She has "accepted" my invitation to join my Family Plan, but she still has her plan (where all her data, photos, etc. resides). I'm reluctant to simply cancel her old (individual plan) until we know all her data is in the NEW location and is protected. Perhaps my question, based on you reply, is: How does she "transfer over" all her data to the Apple Premier One bundle? Does simply accepting the invitation do that? Seems risky. Appreciate your help/insights!

I’m so Sorry, I still don’t understand. My question is what must DO in order to “get her ‘over and settled with her data’ there”??

Does her simply ‘accepting my invitation’ AUTOMATICALLY “move her data over there?”... and how can she “get settled with her data being there”?

Perhaps we’re over thinking it... and Apple has designed it to all happen behind-the-scene ‘automagically’ but no where have I read that’s how it works.

If anyone can advise ‘what we need to do’ to MOVE all her photos, contacts, emails... everything in her OLD iCloud storage account... into MY Apply One Premier account, we’d be grateful. We want to cancel her individual account but cannot before we are sure nothing will be lost by doing so.

Thank you very much.