Yes, it is a figure 8 but if you're on an uninhabited island with a useless aircraft and do not know the name of the island that you're on, might not the "figure 8" comment by AE or FN refer to the general shape of Gardner from the air? Remember also that on charts at this time, the shape of Gardner was different and wrong. This was only corrected on charts published in 1938. So, even assuming AE had a chart for south of the Equator with her, she could not have connected Gardner as she saw it from the air with the Gardner on those erroneous charts.