How to share a Christmas wishlist across households
Use one Christmas wishlist across family gatherings, with a simple plan for duplicate gifts, deliveries, and keeping surprises.

Give everyone the same starting point
You open a cookbook at Christmas Eve dinner. The next morning, someone across town hands you the same cookbook. Both people picked well. They just had no way to know someone else had already bought it.
If you celebrate with several households, give each group the same wishlist link. You can send a different message to each group and still point everyone to the same list. That way, when a link breaks or you change your mind about a size, you only have to update it once.
Make room for different ways of celebrating
One household may exchange gifts after dinner, another may send packages ahead, and a third may only give to the kids. When you share the link, mention who the list is for and whether people should bring gifts, send them ahead, or arrange a separate handoff.
You could write:
A few people asked what I'd like for Christmas, so here's the same list I sent to both sides of the family. If you pick something, please tell Alex privately so we can keep it a surprise. If you're mailing it, message me for the best address.
If you are sharing lists for multiple children or adults, put each person's name next to their link in the message. A relative ordering several presents should be able to tell whose list they opened at a glance.
Decide how people will claim specific gifts
Ask one person who is comfortable knowing about the surprises to coordinate across the different chats. Have them keep a short private record of the item, who claimed it, and whether they bought it. A tentative “I'm thinking about the cookbook” can be held until an agreed date. If plans change, the giver can tell the coordinator and free it up for someone else.
The coordinator can reply with “The cookbook is covered, but the baking tin is still free.” That gives the second person a useful answer and keeps the buyer's identity private. For something you would happily receive more than once, such as your favorite coffee, say so in the entry.
If nobody wants to coordinate, agree to check with one another before buying the few gifts that would be awkward to receive twice. Let people choose freely from categories where variety is welcome, like snacks or secondhand novels.
Plan for the day the gift will actually be opened
For shipped gifts, agree on a delivery address privately and ask the person receiving packages if they can hold them. Add the recipient's name to the gift note if the store offers one. For gifts brought in person, label the wrapped package before you leave home, especially if the same family is going to more than one gathering.
Use the date of the exchange when deciding whether an item can arrive in time. A gift for a lunch the weekend before Christmas has an earlier deadline than a gift opened on Christmas Day. If a package will arrive late, you can agree to open it together on a call or at the next visit.
Leave a few options for the last week
A book from a nearby shop, a favorite bakery treat, or an offer to bring breakfast the next morning gives people a way to participate after shipping gets tight. Give enough detail to make those gifts easy to choose. “A bag of medium-roast ground coffee for our breakfast on the 25th” helps a giver decide what to buy and when to bring it.
Before you send your list, check that every household can find the same link and knows whom to contact about a gift. Two short messages can do the work: one with the wishlist, and a private one when someone chooses an item.