Combining Family Accounts into AppleOne Family

I've gone into chat. I've talked to Apple on the phone. I must not be accurately describing the problem because the solutions offered aren't working. So I'm going to type like I'm a child.

I had an TV and iCloud+ account. I set up a Family account so my wife could backup to iCloud.

My wife has an Music account.

Apple raised the price of TV to the point where having separate apps was now more expensive than AppleOne Family plan which includes TV, Music and iCloud+. So I signed up for the AppleOne Family plan. The chat assured me that by adding my wife to the family plan, she could then cancel her Music and her playlists would sync and everything would be fine.

She canceled and all of her playlists she's built over the years vanished.

I had her sign back up and I was able to get her playlists back and I saved links to all of them. I even added them to our iMac's Music app. But... I cannot edit them by adding or deleting any songs to those lists. I can only play them.

If I have her cancel her Music again, she will have access to those playlists BUT will she be able to edit them since her account created them? I don't want to go through this again.

What steps am I missing here to just have her Music untouched and editable and only pay for Music ONCE?