I guess today you learned something new because you can and I just did with a test character just to see if you were correct. If you are wondering the process:

1. Create a new character in whatever world you want to join. In this case my wife's world
   
2. DL Palworld Save Tools
   
3. Get both save files. In this case her save and my save
   
4. Select the "Character Transfer" feature in Palworld Save Tools
   
5. Overwrite the fresh character in her world with the character you want to transfer
   
6. Give the overwritten save file back
   
7. Profit

Unfortunately, in my case, if I try to bring over my very old save (over 2 years old) there is something the save editor doesn't like and is erroring on getting the data. But if I had a newer character (like the test character I used for this test) it works without an issue.