Apple One - Moving family storage from one family member to another

Hi, I have just subscribed to Apple One Premier, we already have most subscriptions separately across our family used under family sharing. We have my wife and I, and 3 kids under our family sharing account.

My wife however, has the iCloud storage plan (2TB) under her iCloud account, paid at 14.99 in Australia each month, this is of course shared across our family through family sharing.

I now under my Apple one premier plan have 2TB included, and I would like to close my wife’s paid storage plan and move her under my Apple One plan. but I am at a loss on the safest way to do this with our shared data.

How can I get my wife to move from her paid 2TB plan, and move her files into my Apple One 2TB plan so I am the master as such of the storage for our family plan. Do I have to downgrade my wife to the free plan first, before I can join her to my Apple One storage plan?

I am just worried if I downgrade her first to try, that she will loose data or files in iCloud. Perhaps that doesn’t happen, hence my worries and the need for advice first. I guess also, if I downgrade her will I then have the choice for my 3 kids to then join my 2TB under the family sharing?

Many thanks, Sean