How to unlock a locked Apple Account?

Yes, many providers will delete accounts after they have not been used in a while. Even Apple says they may do that, though they appear to not be as rigid about it. Legal - iCloud - Apple

VII. B "In addition, Apple may terminate your Account upon 30 days’ prior notice via email to the address associated with your Account if (a) your Account has been inactive for one (1) year; or (b) there is a general discontinuance of the Service or any part thereof."

If you are only now trying to set up an account for the child and the old address is not working then you need to remedy that. Either contact Google or simply set up a new email account for the child.

If this is instead now an issue of not being able to get access to an Apple Account and there are things of value in it, you will have to try Account recovery. Read this article about how to do that: How to use account recovery when you can’t reset your Apple Account password - Apple Support Account recovery might take a few days or longer, depending on the specific account information you can provide to verify your identity. One tip to using account recovery it to look for options in small blue letters beneath the normal log-in items if you cannot complete the requested information.

Here are links to posts by Community contributors which provide additional detail about the account recovery process and what to do if you do not receive a text or call: Activation Lockout Issues - Apple Community and How can I reset my Apple Account password? - Apple Community and How to delete Apple ID when you can't log… - Apple Community This thread outlines the multi-step process and final recovery —> My Apple ID is locked, how do I fix it? - Apple Community , and this one about things you should and should not do while waiting —> How can I recover my Apple ID after multi… - Apple Community

Does it actually say it is "locked"?

The support article If your Apple Account is locked, not active, or disabled - Apple Support has solutions for three frequently encountered reasons for an account to be disabled/locked/not-active:

● If a message says 'Your Media & Purchases account has been disabled' - Apple Support or "You cannot login because your account has been locked”you might be able to request reactivation by tapping Continue right from the alert, if available. If that does not work, Apple provides a link for this specific issue. Tap or click here and choose a self-help or contact method ➞ https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362 .

● If your account has been disabled for “security reasons” the solution is to reset your password as outlined in this document: If you forgot your Apple Account password - Apple Support

If you find you can’t sign in, reset your password, or receive verification codes, you can request account recovery (read this support article: How to use account recovery when you can’t reset your Apple Account password - Apple Support ) to regain access to your account. More detail in —> Activation Lockout Issues - Apple Community For additional assistance from Apple Security, read: Contact Apple Support - Apple Support

● If your account says “Account [is] locked”, or it is inactive, you might be able to request access to your account by tapping Request Access right from the alert. If that does not work, this link (versus one taking you to the general support page) is the most direct way to get to the people helping you with this —> https://getsupport.apple.com/?PGF=PGF63005&category_id=SC0245&symptom_id=23626

or by telephone at one of the numbers in this support article --> Contact Apple Support - Apple Support

Additional reasons:

● According to various posts, Apple may permanently lock accounts for other reasons (very broadly outlined in section VII-B of Legal - iCloud - Apple ). That may be the case here if none of the previous reasons apply to you. If it isn’t apparent, contact Apple and ask if that is the situation, but don’t expect them to tell you why. You, or somebody who has managed to get access to your account, are likely doing something Apple is interpreting as account misuse. You will have to see if your activities could be construed—rightly or wrongly—as meeting any of Apple's conditions in the support article. You will need to create a new account and stop doing things the way you have been that may have caused the other account to be locked.

In this situation you may be able to still use your equipment with a new account or even no account at all. Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Check the requirements and steps at: Activation Lock support request - https://al-support.apple.com/#/additional-support Apple says, "Proof of ownership documentation is required," but does not detail what currently constitutes proof other than it “must include the product serial number, IMEI or MEID.” Apple may typically require the original receipt* issued by Apple or an Apple Authorized Reseller. If Apple resets the device this will give you access to the device but won't restore access to the account used to lock it. There is nothing that can be done to expedite an Activation Lock request.

*Apple recommends you "Keep your receipt after you buy an Apple device" --> Keep your receipt after you buy an Apple device - Apple Support

● If you deactivated your account, see the section about "Can I reactivate my account?" —> How to deactivate your Apple Account - Apple Support

If it's another reason then post here with details.

Creating a new account is rarely the answer to a locked account. It requires you have the original receipt for the purchase of the devices(s) and also be willing to abandon things to do with the old account.

See this article.

If your Apple Account is locked, not active, or disabled - Apple Support

I am not clear as to the sequence of events. You created a gmail.com email account for your child a few months ago? You are now trying to create an Apple Account for that child?

From what I can tell you haven't even created an Apple Account yet; one doesn't even exist yet, not that it is locked. If it is truly locked then you see a message referring to it being locked/disabled/invalid.

Apple is notifying you that the gmail account doesn't exist? Have you checked that the gmail account does indeed still exist and that you have entered it correctly?