I have done similar with my kids, and they have all earned a ton of points from getting their own cards. But be aware it can sometimes hurt to be an AU.

I had some of my kids with up to 12 AU's on my/wife's Amex accounts. This caused issues for them getting their own card. Calling reconsideration they would ask, "why do you have so many accounts?". And even after I closed their AU, they were then asked on later apps, "why do you have so many closed accounts?" It can raise flags, particularly when overdone as I likely did. They were able to go through on those apps and get the card they applied for, but it likely hurt their ability to get auto approved.

My and wife's latest AOR practically received no auto acceptance. This appears likely due to us as well being added in as an AU on so many Amex accounts last year. We were also asked on recon, "why do you have so many accounts"? To which we would respond, they are as an AU, etc.

Here it is from Experian.

Found this online:

Authorized user accounts can be removed from report upon request
Dear Experian,
Is an authorized user responsible for the debt? If an authorized user is removed from the credit card, can the credit card also be removed from the credit report? I also read somewhere that credit bureaus will not take into account authorized users for credit scores. Is that true?
- CHS
Dear CHS,
An authorized user is not responsible for the debt. However, authorized user accounts will be listed on an Experian credit report as long as the account is current and positive.
Please understand that the credit reporting companies report the history, but do not have the role to “take into account” what is reported. Such decisions are up to the users of the reports.
Most users rely on one or more scoring models to help evaluate the history. Credit score developers determine whether their scoring systems will include authorized user accounts in the calculation. Some credit scoring systems include authorized user accounts in the calculation and others do not.
If you are concerned about the impact on your credit history, you should contact the creditors and ask to be removed from the account.
Unlike being a joint account holder when you share responsibility for the debt, creditors will typically remove you as an authorized user upon request because you have no responsibility for payment. Experian also will remove the account from your credit report at your request or if you are no longer reported as an authorized user.
Thanks for asking.
- The "Ask Experian" team