Yes. Multiple family members can play FINAL FANTASY XIV on the same Nintendo Switch™ 2 console, provided that each player has their own:

Square Enix account
Nintendo Switch™ 2 user profile
A copy of FINAL FANTASY XIV downloaded from the eShop

Please register each Square Enix account to a separate Nintendo Switch™ 2 user profile.

Selecting the appropriate Nintendo Switch™ 2 user profile after starting the console will allow the corresponding FINAL FANTASY XIV account to be used.

For information on creating additional user profiles or switching between profiles, please contact Nintendo.