This article features some material in The Brontës Went to Woolworths that gives me the idea that Rachel Ferguson had personal experience of the problems that creating imaginary relationships and living in fantasy worlds can cause.
She mentions the importance of being very careful when talking in the real world to people who have been the targets of fantasies; she also says that these people must be accepted and dealt with as they really are. She describes some inner conflicts that result from having too many fantasies on the go.
Some of the things that the narrator Deirdre Carne says give me the idea that Rachel Ferguson herself had been in a situation where someone had been part of her life in her imagination long before she actually met them in real life. Deirdre mentions for example how difficult it is to have to treat people as strangers when they have been one of the family for years!
This again reminds me of the double agents in Raphael Sabatini's books who were mentioned in the introductory article: people who live a double life must be careful to keep their stories straight and not give themselves away.
Deirdre has feelings of unreality when about to meet Lady Toddington for the first time in real life. The information that she has either invented or obtained via her researches makes her feel both advantaged and disadvantaged when talking to her.
Deirdre slips up a few times but gets away with it.
She says this about the necessity of bringing Lady Toddington up to speed:
“Meanwhile, there was the spadework of the situation to get through, and I wondered how long it would actually take to bring her up to the point at which I had arrived long since, so that we could all start level.”
I suspect that Rachel Ferguson must have done some similar spadework, slowly putting her cards on the table one by one. How else could she have come up with something like that!