iCloud: switching from individual to family share

How do I migrate my wife from her individual iCloud plan over to my Apple One Family plan iCloud, without losing her data?

My wife is subscribing her own 200gb individual iCloud plan , and i just started my Apple One Family plan subscription with 200gb iCloud storage. Since were already sharing through Family plan, i assumed her service will be replaced with my Apple One but they were separate. Her account is still subsribed to her iCloud and isnt using Apple One. How do i get her to my Apple One iCloud? Should I cancel her subscription first?