Minecraft account privacy

You will need to contact the online support to further assistance regarding this. Access Contact us | Xbox Support. Follow the instructions after clicking on the green button "Contact us" and choose to get help from an online chat agent. Make sure the region on the support website is set to your correct region in order not to find issues with the steps.

As far as i know an Xbox Live account (Gamertag) is required for minecraft on the nintendo switch. To change the
privacy settings i recommend this guide:

https://privacy.microsoft.com/en-us/xbox-one-privacy-and-online-safety

No Xbox One is needed to change the
privacy settings. This can also be done on Xbox.com

*Log in with the microsoft account linked to Minecraft Nintendo Switch

i hope this will solve your problem!

To change the Minecraft Realm privacy for everyone, follow these steps:

Sign in to your Xbox account.
Open the Xbox app and select “Minecraft.”
Select “Settings” and then “Privacy and security.”
Select “Change online privacy and security settings.”
Select “Everyone” to allow anyone to join your Realm, or select “Friends” to allow only your friends to join.
Save the changes.

One of her friends must have their account Privacy Settings set so that only certain content or stuff be shared/played with certain people. This is a big situation with Xbox 360. This is due to someone's Privacy Settings. Get them to change their Privacy
Settings. Usually it's adults/parents who do this to their children's accounts. And yeah, most people on Xbox play Minecraft XD, sorry those who disagree with me, but Minecraft is at or hovering, at the top of the XBL activity charts. Especially on Xbox 360.
I play Minecraft too ^u^

Is the account a 'child' account? If so, see here:
https://answers.microsoft.com/en-us/windows/forum/games_windows_10/minecraft-privacy-and-online-safety-settings/b61e7b37-d332-4be0-b479-8873be04d052