How to reverse and stop sharing contacts to another iPhone? And how to delete only my contact list from that other IPhone - not their contacts also? Help please. I have her email and calendar open on my iPhone.

Hi MsVandrews123,

Thanks for reaching out to the Apple Support Communities. We understand you need some help contacts syncing between devices, and we'd be happy to provide you with the best information.

To get started, when you say that you have her email open on your iPhone, are you sharing the same Apple ID with another person? If so, then this may be expected.

In this situation it is recommended that both devices have separate and unique Apple IDs to avoid this issue. More details can be found in this link here: Make sure that each family member has a unique Apple ID - Apple Support

If you're not sharing an Apple ID with another person, but are signed into the same account in Settings > Contacts > Accounts, you may be able to prevent contacts from syncing with the other device by disabling Contacts for that account. Take a look at this link that can help with using other contact accounts: Use other contact accounts on iPhone - Apple Support

We hope that's able to help.

Take care.