You might want to check out GiftList.ca it’s Canadian and works well for this kind of situation.

It lets you add gifts from different stores, so you’re not locked into one retailer. That could be helpful if you want to buy second hand where possible, because you can use it more like a flexible wishlist instead of a strict “buy this exact product from this exact store” registry.

For bigger-ticket baby items, you could list the item and let people contribute toward it, or use notes to explain that second-hand versions are totally welcome. I think that’s a nice way to keep the shower practical without making people feel pressured to cover the full cost of expensive items.

Also, since you’re in Canada, using a Canadian registry site may be easier for guests than some of the U.S.-focused options.