Wow! It worked this time. Thank you both.
I am sure I followed the instructions before, but it didn't work then. Maybe because I messed up the insert links the first time, and then I kept trying to correct those links, it didn't work. But this time I erased the inserted (blank) photos and started from scratch - and it worked smoothly and easily. Thank you for encouraging me to try again. Even though this 52 Photos 5 is now history, at least I am now not afraid to try again in future 52 Photos challenges.