If you edit your family tree online, please read the following article:
To delete a person in your tree in Family Tree Builder, please do the following:
1. Open your tree in Family Tree Builder.
2. Find the person you would like to delete and open his/her personal card.
3. Click on the ‘Edit’ button and select ‘Person’.
4. Click on ‘Delete Person’.
5. You will receive a confirmation pop-up asking if you wish to delete this person's card. Click ‘Yes’.
Please note:
If you have children attached to the person you are trying to delete, you may receive a notification that the person cannot be deleted. In this case, you need to detach this person's children, and then delete the person.
For more details please read here: