my family and I have have three same Apple ID ...
If you mean your family is sharing a single Apple ID, it's not a good idea to do that for that reason and more.
One person, one Apple ID.
I don’t understand why it’s asking for her info.
It's not. It's asking for information on devices that have been associated with an Apple ID.
Apple has no way to distinguish whose phone it is. As far as they know they are all owned and being used by the same person. To Apple, you are your Apple ID.
To learn how to share Apple products and services among family members, please read
What is Family Sharing? - Apple Support
Set up Family Sharing - Apple Support
Use Shared with You on your iPhone, iPad, and iPod touch - Apple Support