Two people syncing one Ace 2 tracker

[HCGR]

I have a family account for my child's ACE 2.

1. Is it possible for anyone else to set up a family account and synchronise with my child's device?

2. How do I change the name I have registered my child with? I made the mistake of using his actual name when I should have used an alternate name.

The real reason for my question is because I don't want my ex to get data by syncing with my child's Fitbit when he is visiting him.

Moderator edit: subject for clarity

[LiliyaFitbit]

Welcome to the Fitbit Community, @HCGR.

I appreciate your participation in the Forums and sharing your concerns regarding your child's Ace 2 and Fitbit family account. Thank you for providing the additional details, I am here to help. It's possible to set up your child's tracker to another Fitbit family account, but it will be removed from the original account since the tracker can be paired only to one Fitbit family account. In this case two people can't sync your child's Ace 2. For more information about managing your Fitbit family account, see How do I manage my Fitbit family account?

You can change your child's name by doing the following:

1. On the Today tab, tap your profile picture.
2. Tap My Family. 
3. Under your child’s name, tap Switch to Kid View.
4. Tap your child's profile picture.
5. Tap the tile with your child's name.
6. Tap Personal > Display Name 
7. Under Edit Names, tap the name or user name you want to change and enter your changes. 
8. Tap Save.

For more information, see How do I change my name or user name?

I'll be around if you have any questions.