The Reverend Mother visiting the Baron makes no sense

The Reverend Mother Gaius Helen Mohiam (the old lady people saw testing Paul early in the story) has an interesting background, part of which is top secret, classified info among the Bene Gesserits. Even Lady Jessica didn't know this particular Reverend Mother's role in the past regarding the Baron Harkonnen.

Spoiler alert:

When she was young (and not a Reverend Mother yet), Helen Mohiam was actually young and beautiful, and part of the Bene Gesserit Breeding Program, taking part in helping to make the Kwisatz Haderach. She was given the alias of Tanidia Nerus, and sent to conceive a daughter with the Baron Vladimir Harkonnen. Now keep in mind, this was almost 40 years before the events of "Dune" took place. When the Baron was young, he was actually a handsome, athletic, formidable warrior and politician. He was still an evil, sick bastard, of course, and wasn't exactly a fan of women, if you catch my drift. Helen got him to sleep with her through blackmail and threats. She then left the Harkonnen court to bear the child on the Bene Gesserit HQ world. Trouble was, the baby born from that union died soon after birth. So Helen was forced to go back to Geidi Prime and do it with the Baron again. He was ready for her this time, and had her paralyzed with a poison she wasn't familiar with, and raped her. However, he should have known better than to do that to a Bene Gesserit. Members of that order have complete conscious control of their bodies all the way down to the smallest molecule. In the process of nullifying the poison with her mind, she also created the world's nastiest STD and infected the Baron with it, which led to his muscles being destroyed over the next 30 years. Only reason he got so severely obese was due to him being a hedonist, including when it came to food. So despite the rape being a horrifying experience, Helen was able to conceive a healthy, strong daughter, which was named "Jessica." The Order didn't tell the Baron he had a daughter, and they only used Helen's alias when telling her who her mother was, and Jessica was raised by the Order, like many of the girls brought in. She never knew her boss was also her birth mother.

So for the Reverend Mother to ever return to Geidi Prime and speak directly to that same vile monster, for any reason after an experience like that is out of the question. It wouldn't even matter if the Baron didn't recognize her, she would still remember him.