Miss Stuart anyone?

Emily Hahn, on whom I posted yesterday, writes of a British Museum (library) reader she identifies only as Miss Stuart, who the writer saw on her first day at the museum (which must be late Twenties or very early Thirties).

""She rode past me on a bicycle, through the opening in the great iron railings and across the courtyard .... She had a jaunty manner ... but there was more than that to be noticed about Miss Stuart. On a cold, raw, dark day in January, in an era when women never wore bifurcated clothing for anything but the most drastic activities, she was attired in very short running shorts, a cotton sweater without sleeves, and socks ... (p. 127)

After the war, Miss Stuart's costume "is covered, winter and summer, by a frayed macintosh ... and she now wears a hat as well - a thing like a basket pulled down over her straying, pepper-and-salt hair".

And she has also got a bit strange ...

Hahn is told another reader saw her spitting.
"She would spit on a page, then turn it over and spit on the next. She was very careful not to miss a single page..."

The book was Lives of the Popes, and when this neighbouring reader reported her an attendant came, saying: "Now Miss Stuart, you know you aren't to do that. You've been told before." As she was led away, Miss Stuart hissed "Papist spy" at the informant. (p. 136-7).

I don't suppose anyone knows any more about "Miss Stuart"?