As long as the photos are in your own FaceBook account, you can share them again. I say again, because they are normally shared when you add them the first time.
- Go to your own profile by selecting your name in the left sidebar.
- Select the Photos tab. It should be just under the header picture and your avatar.
- Navigate to the photo, until you are seeing it full screen.
- At the bottom left, select the three dots (. . .) and then Share.
- Change the TO: field to reflect who you want to see the photo
- Add an optional comment
- And tap Post.
Alternately you could tap the comment icon (instead of the dots) and add a comment to the photo. This will 'usually' pop the original share/post near the top of your friend's timelines. Though, with FaceBooks weirdness it might not.
If the pictures are in someone else's FaceBook account, then what you can do with them will depend on what permissions that person has granted. You may only be able to comment on them, which will show up in their timeline, but may or many not show up in yours or your other friends; again, depending on permissions.
You may be able to copy the picture to your camera roll and then post it. Again, depending on permissions. Personally I would never do this without getting the consent of the other person(s) involved. At the very least you are risking your friendship.
Everting I described is using the FaceBook app. It is 'probably' still possible to do this in Safari, but the details will differ.
Good luck.
