I would stay awayfrom the desserts as a low carb dessert is unlikely to fool anyone
How about something like meatballs, with sauce on the side? Or bacon wrapped baby smokies?
Taco dip is nice (sour cream/ cream cheese on bottom, followed by cooked hamburger with taco seasoning, and then finely chopped green onion and bell pepper, and olives if desired, and then shredded cheese, serve with a spoon and scoop tortilla chips.. You could eat yours with a fork.
Caesar salad? Pick out the croutons. Or even a crudite platter with low carb dip.
Chicken salad with mini croissants? You could just have a scoop of chicken salad.
I have never heard of a potluck shower.. I thought that was the hostess' job??!