Don't forget there were many other occasions on which the girls may have received jewels as gifts. Not only their birthdays but also Christmas and possibly Easter. And don't forget, as devout members of the Russian Orthodox Church, each member of the Royal Family would also celebrate, once every year, his or her appropriate "name day"--the feast day of the saint after which each was named. In fact I have heard that in religions which recognize "name days", the name day at least in a religious sense is regarded as more significant than even the person's birthday. For sure each girl would have had a party and received beautiful gifts on her name day. Actually one of the last jewelry-gifts from Alexandra to any of the girls was a gold charm bracelet she gave to Marie in, I think it was 1917. It was a bracelet that had belonged to Alexandra herself and in her "jewelry book" she wrote that she had given this bracelet as a gift to Marie. I checked the date of the gift and the date of Marie's name day (she was named after Saint Mary Magdalene). I was not surprised to realize that Alexandra had given the bracelet to Marie on the feast day of St. Mary Magdalene, i.e. Grand Duchess Marie's name day! So clearly the girls were known to receive gifts of jewelry on their name days too.