Hear me out - shower but not wedding invite

Shower guests must also be invited to the wedding. Period. Tell mom to uninvite asap. The only exception is a shower hosted by coworkers, your house of worship, your local book club, etc who know they aren't invited but want to share your happiness.

It's one thing when brides intentionally want to invite people to their shower but exclude them from the wedding, but it sounds like you had no intention of that, so I don't think you should have to pay the price for your mother's faux pas (and that's putting it nicely). She has really put you in a bad position, but personally I wouldn't extend a courtesy invite at this point.

Etiquette aside -

The real question is: if they get upset, will you care?

If so, then you should probably invite them even though it sucks. If all you're going to think about is "should I have invited them" "oh man I should have" "ugh I feel awful", save yourself the negative thoughts and just invite the one you like (even with her partner). Sometimes, at least for me, I feel like thinking about the situation ends up being more stressful than the actual thing. If you're worried about the alcoholic, you may want to give your DJ or coordinator or someone a heads up to keep an eye on them and trust they'll handle something if the situation arises.

If you'll only be upset about it for a day or so (or not at all), then honestly who cares (not including random people from the internet who always have strong opinions one way or another)? I'm all for etiquette, but your mother is the one to blame here even if it wasn't intentional. At the end of the day you need to do what makes you happy on your big day. This is a wedding, not something someone is entitled to - especially someone you don't like. You don't really get a re-do, and for me, I want to make sure I'm spending money on people I actually like haha

I'm going to be the jerk - this isn't on you, so don't invite them.

If they ask why they weren't invited, I would politely direct them to your mother and let her know that she can explain that she overstepped by inviting them without your knowledge when they were not on the wedding guest list.

Of course, something tells me that if your shower was a month out from your wedding, and they hadn't already received an invite, they may know they aren't invited. This may have been a ploy to shoehorn them onto the guest list, so they may not dare ask about not being invited to the wedding. If I was invited to a bridal shower by a bride's mom, a month before the wedding with no regular invite, I would have gathered that I probably wasn't on the wedding list.