Thank you to Walt and H_d for your prompt replies.
I have now found the "snapshots" window, which I had no idea was there, it was hidden at the lower right hand edge of the screen, but on dragging it up I found it and worked it. Perhaps because I work solely on a 17" laptop the page displays differently to a PC? Or I haven't organised the display for my purposes. I am a beginner so I have many possible errors.
I have now worked on two flower photos of my own, using focus stacking. The second one worked much better than the first, so I am going to work on a third flower picture today and practice. I hope that this one is acceptable to print.
Thank you again,
Beverley