Gmail – How to recover an account that was converted to a Google “kids” account and immediately blocked

The primary email address of your Google account was "converted" to an alternative email address when you added a Gmail address for your daughter.

From Remove addresses from your account

Here's how to remove an alternate email address from your Google Account:

1. Sign in to your account at myaccount.google.com.
2. Select Email in the Personal info box.
3. Select Edit next to Other emails.
4. Under "Change your associated email addresses," select the "X" to Remove.

See what usernames you can remove from your Google Account.

Using Thunderbird, setup to connect to two accounts, you can drag emails from one account to another. Just select the emails you want to move, and drag and drop to your desired destination.

I don't remember if you can even define rules that will move the emails automatically between accounts.