I had uploaded some ancestor and family photos onto Ancestry and Find A Grave. A cousin contacted me about purchasing her books she had published on our family history. After I purchased her two books, I had found my photographs published in them. She evidently collected and used any photograph she could find and included them in her books. After I contacted her about my personally owned photographs of my ancestors, her response was that since I didn't personally take the photographs of my ancestors, aunts and uncles myself she could legally do as she pleased. Even headstone photographs from Find A Grave was published in her book with no credit to the original photographer. Was this legal for her to do?
She's right: If you didn't take the photographs personally, you don't own the copyright and can't prevent her publishing them.
The person who took the photograph (and so originally owned the copyright) could, or the person/people who inherited the copyright for up to 70 years after the photographer's death (in the US: terms elsewhere will vary). If the original photographer has been dead for more than 70 years, the photos are out of copyright and she can do as she pleases. And if the original photographer is unknown, there isn't much anyone can do to stop her either. See Copyrighting that photo.
The FindAGrave photos will probably be in copyright, but she may be allowed to use them, depending on what rights the photographer granted when they uploaded the photo -- see Permissions and the tombstone photo for more on this.