There is no such option to transfer old data of more than one Gmail to new Gmail account.
You can even pick and choose what to forward.
Update Your Email Address on All Your Accounts The annoying part of changing your email address is updating the information on all of your online accounts.
However, Google notes that these filters are not perfect, so explicit, graphic, or other content you may not want your child to see makes it through sometimes.
Email addresses end as protonmail.
Here you can choose whether to keep your phone number linked to your account and whether you want to add a recovery email address.