I am in the same situation. My good friend's daughter, who is 23 and very mentally unstable, is getting married in May. I already bought them an engagement gift (thankfully, we were on a cycling trip at the party) and now her shower is coming up.I have to miss a Sunday of cycling for this. I spent $50 on the engagement present, so I am getting her a more personal type of present, maybe back to the days of the trousseau. I will have to buy a wedding gift too, so the shower gift will be small. I am ignoring the registry. I should get both of them a prescription for a nutritionist, because they both weigh over 300 lbs. Don't get me started.
Indi., I had the same type of wedding. 20 people came to our apartment and the rabbi arrived with a portable huppah (canopy). Then we took everyone out to dinner at a nice restaurant.