Re: PvZ2 and heartbroken 7 year old kid on Valentine's Day :(
Tap on the white gamepad🎮 at the bottom right hand side of the screen and IF Google play has your data then the next screen that pops up should be from google asking you to select your account.
Select your account and IF it syncs then "tap to enter" should get a number after it. Go through the list and see if his profile is there. I presume he hasn't got his player i.d.?
The "tap to enter" is a new profile that starts from the very beginning.