I have a suggestion. Have something other than a shower -- make it a recipe shower or an advice shower, or even just a lovely little party or "tea." When I got married, two people each gave me a recipe shower. You enclose a pretty recipe card and a stamped, self-addressed envelope to return it to you in the invitation. At the party, you give the recipes, compiled into a book or a file, to the bride. (Those are my dearest treasures today; over the years, I have asked other very close friends to contribute, too, and someday I know my children will enjoy having them.) I think that for such a party, it would be fine to invite people who aren't invited to the wedding (especially because the wedding is small).

Have fun!

However two others were for brides that were having very small weddings, immediate family only. I knew the brides well and was thrilled to be part of the celebrations!

Think it depends on the people and circumstances. If you have any doubts how the event will be received have a giftless shower or an old fashion trousseau tea!

While I'm at it, I don't like the term "couples shower." I think the idea is that it is for both men and women, right? But not everyone is part of a couple. What's wrong with just calling a coed shower a "shower"? There is nothing about that word, other than people's sexist assumptions, that implies that the event is just for women unless specified otherwise.

For your party, which sounds like it would be mostly relatives and close family friends, I would LOVE to see a story shower. Have everyone tell an anecdote
about marriage or about the bride or groom. Either have them written up in advance, or record them being told and have someone transcribe them, and compile them in a pretty album that you give to the bride (keep copies for yourself). If I were the bride, I'd definitely prefer that to a whole carload of shower gifts. There's your entertainment, too -- much nicer than silly games. I once went to a shower where we each pulled a marriage-related topic out of a hat and had to give the bride a piece of advice related to it. It was so fascinating, especially because there were women of all ages. It started off great conversations for the rest of the party, too. I don't even remember if there were also gifts.

I agree that circumstances dictate whether it is "okay" to invite people to a shower who aren't invited to the wedding. A bride or groom's office friends might want to have a little shower, lunch, or drink, to which they would probably invite the whole department or whatever the appropriate unit is, even though obviously they can't all be invited to the wedding. People would know to give small gifts, or just not attend at all, under that circumstance. Also, if the bride and/or groom live far from where the wedding will be, their local friends and colleagues might want to give them a shower or other party even though very few if any will be invited to, let alone going to, the wedding. I think chase put it very well with her examples. It's one thing to invite people who absolutely wouldn't expect to be invited to the wedding, especially if it doesn't feel like large gifts are expected, but quite another to invite people who just didn't make the cut for the wedding to a big-gift shower.