"Wynter’s veil had concealed not only her face but a wireless radio."
Isn't that pretty advanced for 1919? A wireless radio that fed her information through an earpiece?
There has always been a very lucrativ market for an engineer+magician that could provide hidden communication devices at the fringe of technology.
One of the best and oldest device I found used a telegraph (!) hidden in a turban and shoes with copper sole on a copper threaded carpet.
Radio was invented in the second half of the 19th century, so pretty mature by then. I guess a sufficiently miniaturized earpiece does sound impressive for the time, but it seems likely the radio itself would be too bulky and was likely hidden somewhere in her clothes.
Easier in the times before the fcc let's put it this way