Hello there,
Yes, you can link your personal account to the family account you will create.
Switching to the Microsoft 365 subscription that best meets your needs is easy. For example, if you have Microsoft 365 Personal and want to share Office apps and subscription benefits with your household, you can switch to Microsoft 365 Family.
Here is how this works https://support.microsoft.com/en-us/office/switch-to-microsoft-365-family-or-microsoft-365-personal-3fcc1efc-2722-427f-8efa-db94b9b0a36b
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