How do I change gmail account on tablet?

resetting system wont clear your account password or account need to open account and click the change or edit password / account info

Gmail allows you to ask for forgotten passwords.
If you're hacking someone else's account be aware they if caught by the person you're hacking they can press charges against you!

click on forgot my password and change it. Someone might have stolen you password.

You will have to log in to each account and delete them one by one, and clear your cachet, restart the tablet, use the one gmail address for everything on the tablet, make sure you dont have multiple gmail profiles, nothing should change on its own, you may have been hacked, report this possibility to gmail admin, check phones firmware & update if needed, may have to restore factory settings to be safe, but back up first.

HOW TO VIDEO

If you change your password to the acct. she will no longer be able to access your acct.

Best to sort out your account on your pc or by phone
Google Help

Your Xoom will automatically prompt new password if your gmail password has changed. In your browser go to One account All of Google to change your password and then use the same password on your Xoom.

Mark
Motorola Support

You should be able to change the address under Setting> Accounts and then select the one you want to change or delete

I am guessing that this actually involves your GooglePlay account and not the Meep parent portal account, as all Meep parent accounts use a parent's email and the emails don't go to the tablet in any way, other than through the Meep Together parental contral app which would involve a password to access. We have had people use their personal Gmail accounts for the Meep's GooglePlay and have this happen. This is why it's recommended to create a new Gmail account just for the Meep. The best thing to do is Open GooglePlay and change the account, creating a new one.