If prepared in Online TurboTax, we can tell you how to find the account. Hopefully, you prepared the return in the son's own account and did not try to prepare 2 returns in your own account. If you prepared his and yours in the same account, the second return would overwrite the first one. So, hopefully, you have multiple accounts and are just signing into the wrong one.
I'll tell you below how to look for multiple accounts and restore access.
