I've recently purchased the OLED Switch and transferred all my data over from my old Switch to the new one.
We both have Nintendo accounts, but based on the research I've been able to find it appears only the primary account on the Switch (my account) would be able to switch game data over.
No it's not. This is likely a misunderstanding. My old Switch had 2 accounts, one belonging to the Japan region for the purpose of downloading a DLC for a game I had purchased in Japan. I managed to transfer both accounts without a problem.
According to Nintendo Support:
A Nintendo Account must be linked to the user account you wish to transfer from the source system. That same Nintendo Account cannot be linked to a user account on the target system prior to the transfer.
The misunderstanding probably comes from the fact that you can only transfer accounts that are linked to a Nintendo Account (which is required to use the Nintendo eShop), but has nothing to do with whether the account is the primary owner of the Switch.
- If so, is there any way to make her the primary account holder on my current Switch so she can transfer her data to the new Switch and then I just have to start over?
This is likely not necessary. A Nintendo Account can only own a single "Primary Console", but a Switch can be the "Primary Console" of multiple Nintendo Accounts. This is to limit instance of game sharing, where a single account buys all the games, which many people can play by simply having that account on their console. The owner of the games can play these games on any console, but other accounts can only access these games on the "Primary Console" of whoever owns the games.
- If I had two Switches, would I have to re-purchase the games I've already paid for?
No, you wouldn't. Physical copies can be played on any console, as long as the cartridge is currently inserted in the console (assuming there are no malfunctions). Digital copies, meanwhile, are tied to your Nintendo Account. No matter which Switch you use, you can download and play games you've purchased as many times as you want.
Your girlfriend might lose access to games you've bought, though, and you would lose access to her games.
This is where the "Primary Console" comes into play. Technically, you can make your Switch the "Primary Console" of your girlfriend, so you can play her games. Meanwhile, your girlfriend's Switch could be registered as your own "Primary Console", allowing her to play your games instead.
A few things to keep in mind:
After you transfer your girlfriend's account, her account (and all her progress) will be removed from the old Switch. If you want to access her games, you'll need to create a new account and link it to your girlfriend's Nintendo Account, before you can make your Switch her "Primary Console" and access her games.
The transfer only affects users and their save data. You will need to redownload any games to the new console before you can play them. Miis are also not transferred, but can be copied separately through the Mii Maker in the System Settings.
If you want to be able to play on either Switch and still keep your progress on both, you'll need an active subscription to Nintendo Switch Online in order to have access to Save Data Cloud Backup. Some games are not compatible to Save Data Cloud Backup, and can only be transferred from one Switch to the next, but not synchronized across multiple consoles. Games that don't support Save Data Cloud Backup include:
- Animal Crossing: New Horizons
- Pokémon Let's Go, Sword/Shield, Brilliant Diamond/Shining Pearl
- Splatoon 2
- and many more
Save data from Animal Crossing: New Horizon can not be transferred using the Nintendo Switch data transfer process. According to Nintendo Support:
Save data that is shared by all users on the system, including Animal Crossing: New Horizons save data, will not be transferred with this process.