I had a few people go in on bigger gifts together at my wedding shower, and I sent each person their own thank you card.
I also made sure to make each note personal and a little different. I figured if they're close enough to purchase gifts together, they'll probably be talking to each other about receiving the thank you card.
I would definitely do individual notes for that number. On the other hand, if there were about 30 people who put in for a package of pampers, I would reconsider.
Completely agree that you should go individual. I also like to add "Thanks for attending my/baby's special day" in the thank you note so I'm not just thanking them for the group gift, but for their individual attendance too.
Re: Shower Thank You Note Question
Individual. The TY card is to acknowledge that they put thought into getting you a gift, not the gift itself.
You should always acknowledge gift-givers individually.
I had a few people go in on bigger gifts together at my wedding shower, and I sent each person their own thank you card.
I also made sure to make each note personal and a little different. I figured if they're close enough to purchase gifts together, they'll probably be talking to each other about receiving the thank you card.
Make a pregnancy ticker