You can list you family relationships on your Facebook profile.
Adding your siblings and other family members to your Facebook information allows you to highlight people who are important in your life. Your profile will show the relationship of the family member, along with a link to the other person’s Facebook profile. The family member must confirm the relationship before the information appears on your Timeline. You can add only family members who are on your Facebook friends list.
Go to your Facebook timeline and click the “About” link under your profile picture.
Click the “Edit” button in the “Family and Relationships” section.
Type your sibling’s name in the “Family” field.
Click your sibling’s name if it appears in the drop-down list. Only people who are your Facebook friends will appear in this list.
Enter your sibling’s email address in the field beneath her name, if prompted. You will be asked to provide an email address only if your sibling is not on your friends list.
Activate the “Choose Relationship” drop-down menu and indicate whether this person is your “Brother” or “Sister.” You also can choose “Stepbrother” or “Stepsister.”
Click the “Save” button. The change will not appear on your profile until your sibling confirms the relationship.
Tip If your sibling is already on your friends list, she will get a notification asking her to confirm the relationship. She can find the notification by clicking the toolbar icon that looks like two people, and then clicking the “Confirm” button on the notification. If she doesn’t see the request, she may have to click “See All,” and then scroll down to the end of the list.If your sibling is not a Facebook friend, she will get an email with a link she can click to add you as a friend and confirm the relationship. If your sibling is not on Facebook, she will first have to create a Facebook account and add you as a friend