Good luck with that.
When you reinstall pvz2 it installs a fresh version with a new player i.d.
If you could have synced it with your Google play account then you would have also got back your old player i.d. as well as your profile.
EE HELP CENTER has a habit of insisting on player i.d. numbers because it makes life a lot easier for them so you might have to be persistent.
clear the PvZ2 data and cache via your phone settings under APPS
after reopening PvZ2 tap the Google Play icon in the lower right portion of the screen and it should recover all profiles that exist
good luck and I hope it works for you and your child
