Hyacinth has simply got to have it. She is reduced to working herself into a lather of repressed sexuality on the organ and now that is the only way she can get the release she needs to function as a fully liberated woman.
The scene that Rose walked in on in her sister's house with her Brother-in Law and the babysitter was not appropriate for mixed company. She decides that he needs proper punishment for his cheating ways and she might scratch her itch at the same time.
This should perhaps be more accurately described as speculative fiction regarding the near future of the medical field. With everyone growing up with the internet and generally much more exposure to sex and nudity, I expect that a number of factors will result in a lot less bodily modesty and greater acceptance of public nudity and sex. And the economics of the huge expense of modern medicine may force a lot less concern for privacy.
This story is written across several different genres and is difficult to describe except in the sense it is historical, time-shifting, science fictional, romantic, erotic, fiction. The lead character is female and conflicted about her own sanity. Read carefully to determine what is reality and what is fantasy.