In
The Queen's Jewels Leslie Field (p. 108) stated that QEII had worn a pearl bracelet with a large sapphire which Queen Alexandra had worn at her coronation.
This is a cropped version of the photo of Queen Elizabeth printed in Field's book.
Field only identifies the occasion as being in New Zealand in 1954.
The photo was taken in Christchurch, New Zealand in 1954.
Below is a copy published in Australia.
Although this photo is low resolution it does show that the image used by Field had been retouched for publication.
I strongly suspect that the bracelet worn by QEII in Christchurch was Empress Marie's pearl and sapphire choker worn as a bracelet.
Queen Elizabeth was definitely wearing the choker as a bracelet during the Australian leg of the tour.
In Sydney
And in Hobart
Detail
The other reason why I am sure that QEII was not wearing a pearl and sapphire bracelet which had been worn by Queen Alexandra at her coronation is that Field is obviously mistaken, Queen Alexandra's bracelet was four rows of diamonds with a large gemstone surrounded by a diamond border -- not a pearl in sight.
Queen Alexandra's bracelet. The same bracelet from various photos.