Can I use Family Sharing with an Individual Apple One account?

I currently have a Family Plan on Apple Music which is assigned to a “parent” Apple ID. I was basically sharing it with my daughter. Because we didn’t want to share the same music (God no!) we had two other Apple IDs (one for me and one for her) as members under that plan. Think of them as sub accounts or members of that parent/family account.

She’s now on her own and has her own individual music account. So I no longer need a Family Plan. I want to switch that parent account to an Individual account. Here’s the problem. All the music I’ve added to my library and/or downloaded is to the sub account Apple ID. However the parent account was used to purchase movies and tv shows. Obviously I don’t want to lose the movies or all my music downloads, but they are on two different accounts.

I was thinking I could change the parent account to an Individual account. And through Family Sharing, still be able to have my old sub account, retaining all my music. So my question is, can you Family Share an Individual Apple Music account across two Apple IDs??

Or is there some solution to consolidate everything to a single account?