The iPhone is most probably not the only Camera you or your family might be using: There are also Samsung Galaxys, Nokias, SLR-Cameras and more. As a photo-lover or member of a family you might be taking pictures with different cameras and mobile phones.
Typically, all these photos are aggregated and stored either on your PC or laptop or on a NAS (Network attached storage), in many cases in Dropbox.
When putting together and selecting the best photos from a family-vacation to make an album more than once you might want to edit them in various ways like
What are the issues you are facing?
But
Use the Pics2Phone App to download photos to your iPhone, then edit.
With the Pics2Phone App, all Photos can then be downloaded locally to the iPhone's native photo-App for editing.
Just open the Pics2Phone App and press "Download", then open the respective Photo-App (see some of our recommendations for Photo-Apps here) and edit the photos as if they were taken with the iPhone itself.
When finished editing, use the Dropbox-App to re-upload the photos to the sub-folder "Edits" within the "Pics2Phone"-folder.