Similar story here https://community.fitbit.com/t5/Android-App/Moved-to-Google-can-no-longer-access-children-or-other-p...
In order to be able to see child accounts after moving to Google, the child needs their own mobile phone to login to the Fitbit app
Or you need a phone that supports profiles and completely switch profiles to access one app
The whole point of devices like the Fitbit ace is for young kids, who typically don't have phones. Be warned as there is no warning before you migrate that you will need a separate phone to access each child account afterwards
