How old are they?
The minimum age for Snapchat is 13. The direct mesaaging part of it allows for fun and harmless messages between friends. I think allowing her to use it if she's 13+ is reasonable.
What you could do is to ask her not to allow friend requests or messages from anyone who are not her friends, not to use the AI assistant (which can't be disabled), and to not use it to consume content from influencers (which is in a separate tab to the right). You cannot really police this, but it's not the end of the world if she sees the feed of some dumb influencer. Maybe while she's home you can show interest and use it together with her.
Position data must of course also be disabled. Snapchat is a bit creepy.
The fediverse is always (somewhat) public, making it not inherently child friendly. Getting together with other parents to set up a Pixelfed instance to use in the friend group rather than to have them use Instagram is a cool idea, and allows parents to be admins and decide who can federate without taking control of the accounts of the kids. It might be a nice way for them to learn that whatever they do online is run by some person whom they decide to trust. And it could keep them off Instagram a little longer.
I don't really know the first thing about parenting though, just my thoughts. It's a tricky question.
I think solutions to this is of a very individual nature - it's hard to imagine a universal solution.
But it seems your addiction might be to beer more than to alcohol itself, for now at least. And (some) alcohol free beer has gotten really good.
So my suggestion is this: Next time beer is on sale, instead of buying a six pack match the value in buying alcohol free beer. When you're back home you can still pop a cold one, it still feels like a nice reward, and you don't feel bad after. And you don't run the risk of developing an addiction to alcohol.
I never had a drinking problem, but I try to always keep alcohol free beer in the fridge these days just because I think it's a nice treat after a day of work or whenever.