I'd like to create a GOG acct, buy a few games, then give it to my daughter for Christmas. Possible? If so, how do I do it?

I'm pretty sure doing that is very much against GOG's terms of service, and if you did do that, then the "gifted" account would be subject to being banned if GOG felt like doing so.

You need an email address for that account.
Set one up, create the account, buy the games, then gift the email (and the account details) to your daughter.
Done.

-edit (because I got excited and clicked 'post' before I entered anything - jeez)
I was thinking along those lines myself. Don't want to get in trouble if there's some problem with doing so, though.

Even if against the ToS it would be not very likely to get into any trouble especially if you live in the same country (but even if not I honestly doubt GOG actively checks for possible traded accounts).

But to be 100% at peace yoy can just buy gift codes and let her register herself.

I'll start by saying that on the face of it, it would seem to be a breach of 3.3 ("Your GOG account and GOG content are personal to you and cannot be shared with, sold, gifted or transferred to anyone else. Your access to and use of them is subject to GOG’s rules which are set out here, as updated or amended when necessary." https://support.gog.com/hc/en-us/articles/212632089-GOG-User-Agreement?product=gog)

That being said, I'd agree with you that it's not unreasonable behaviour proposed by OP as the sole purpose of the account would be for her use - and if it's set up using her details from the get-go then I think there's an argument to be made that it's okay.

Term 1.5 might also have some bearing here:

1.5 If you're over 18, then welcome! If you're between 16 and 18, before we extend an equally warm welcome, please ask your parent or guardian to review and approve this Agreement on your behalf (because in some countries people under a certain age cannot legally enter into contracts like this Agreement). If you’re not 16 yet you cannot have a GOG account or use the GOG services because legally we cannot handle personal data of children without a special parental or guardian’s permission (but your parents/guardians are welcome to sign up themselves).

This implies that parents can sign up on behalf of children.

No one will know or care that you set up an account for a family member and bought games on it. I'd just disable two-step login before handing over the login credentials, to make it easier to change the e-mail address.

Alternatively, you can just check "Gift this order" at checkout time. You can enter your own e-mail address as the recipient if necessary. You then have a redeemable gift code you can share with the giftee. You can also find the code in your orders history.

Instead of "gifting" an entire account, is there a reason your daughter can't just set one up herself with your supervision and simply use your card to buy the games?

Or even simpler, just buy the games as a gift and send the code to her email as Ice Mage already suggested. If necessary, he can then still help her with setting up get account but without all the unnecessary fiddling with payment methods and such...

This is what i was just thinking. The only downside is if she's under 18 then the newer adult content may be inadvertently shown to her at some point. (Need NFW/NSFW switch).

Otherwise, setting up an account assigned to her and putting money in her wallet can work.

Alternatively you can always buy games as 'gifts' and then give them to her when it's time and have her redeem them.

edit: Seems a lot of people have suggested gifting codes... This is true too. If you DO end up doing that, simply don't declare you've done it. If they don't do something stupid nothing will happen.

Besides creating a clean account in which you're say claiming free games and/or putting money in a wallet before handing it over is hardly reason to ban block or otherwise. Hard to abuse that.

The worry i think is that you'd have say 1000 games, and then passing it around. Although legally you'd own the right to do it, and under UK law (which GoG is surely following to sell there) by law you can sell your digital games the same as physical, so handing an account over shouldn't be an issue. (Sharing/loaning on the other hand... that's just asking for trouble)

I would agree with the gifting the codes, but there's plausible reason their daughter doesn't even have an account yet, which is why I'm suggesting they simply help them make one if need be.

I was hoping for the whole thing to be presented at x-mas as a complete surprise (rather than a project for her to do).

Also, two facts that you've touched on: 1) Daughter is 40 years old, 2) we live in the same apartment and use the same ISP/router.

Sounds too old fashioned. That's kind of like surprising someone by signing them up for a spa membership or something. And if they're 40, you might as well just ask them if they have a GOG account in the first place. If they don't, doesn't hurt to probe their interests if you advertise it to them.