A Chinese name has control of my Family Sharing

there is a contact link.

Apple ID Support

Apple ID Support (2)

Apple Support by e-mail or chat Select your device, Battery, Power and Charging, then Power adapter not working to get a chat option. If the initial contact can’t help you, ask them to have someone who can help contact you.

Apple Support using Twitter

Or fill out and submit this form.

You can contact Apple phone support as they will resolve this issue.

Contact Apple for help with Apple ID account security - Apple Support

Before blaming Apple for this, get the facts right, it is important to note that the decision to share your photos with strangers was solely yours. People get sucked into scums because they think they can save this world.

There is somewhere in your iPad to solve your problem.

Solution

On your iPad or iPhone, Open the Photos App, select Shared, you will see all the shared albums both from You and the other people.

Case 1 I am assuming you are the one who created the shared Album

Select Albums from You, below the page that comes, select People.

Now you have 2 options, to delete the album, this will not affect your photos as they are still either on your device or iCloud. You can go ahead and delete.

Option 2, Click the contact that you want to block, then select Remove Subscriber.

Case 2 I am assuming you were invited to a shared Album and in your kindness you accepted in the spirit of mate-ship (LOL @.au).

Select Album, select People and click Unsubscribe.

The above should solve your nightmare but please note that if the other party has been downloading your photos, you cannot do anything about it.

Case 3 I am assuming stolen Identity

Your apple ID is linked to your devices and phone number, you can simply change the password and block the Chinese user, use 2 factor authentication.

If you own the Apple ID you should know the answers to your questions to reset your password.

Finally, this may sound silly advice but different countries including China have different laws and they block certain features their citizens' phones for their own good reasons. It is important to stick to what your country allows you to do. In trying to help the Chinese person share photos you may have exposed yourself as someone who helps Chinese people avert their legal system and this carries a life sentence in China but not in Au.