Othar is a good example. In her world, the relationship between the Wulfenbachs and he started out as stormy as in the GG world. But when she was 14, he captured her -- claiming he was going to kill her, but not doing anything of the sort. She realized that he was simply too good a person to commit murder like that. She slowly talked him around, until he not only let her go, but became a valued (if somewhat unpredictable) ally. Relations with him have been strained over the past couple of years: she depended on him at the beginning, but as she became harsher in her attempts to control things, he became uncomfortable with her. She regrets that terribly, since he was one of her closest friends before then. Note that the real Othar recognizes her as "the villain's daughter" instinctively, and understands the cliche that she must become an ally. (Indeed, we should think about how to expose Othar-vision to him.)
DuPree is one of her closest friends. She was 10 when DuPree joined the Wulfenbachs, and just mischievous enough to find her a kindred spirit. The two of them joined together to make Klaus completely nuts. She softened DuPree's harsh edge, essentially acting as her "Jiminy Cricket" long enough to turn her almost sane. And since she was forced to take over, DuPree has been her most loyal subject and ally, helping her bring things under control. She has been trying hard to solve the Brigadoon Effect for her; that was her principal reason for learning more about Amagog, which took her to TPU.
She knows Moloch, having gone searching for him specifically once she figured out the Amagog/von Zinzer connection about two years ago. She doesn't love him, but gave him a job as a captain in her army: he is brutally efficient, if a bit angry and moody. She knows about the Incomplete Brooch, and has hypothesized that it is the [Reality Stabilizer]?. The Hidden Castle appeared about a month ago, apparently spontaneously (in fact, due to ripples from Beetle shorting out the shifting device in this reality), and she had come to it specifically to see if it contained the missing piece of the Stabilizer.
She was also hoping to help the Jaegers get access to their world, but she doesn't quite trust Jenka -- she has empirically determined that she is not bound to the Heterodynes the way the other Jaegers are, but neither has ever talked about that. She doesn't know what Jenka's agenda actually is. She doesn't particularly know Dimo, Oggie and Maxim; if she asks, they look vaguely familiar, but they are just ordinary soldiers in her army.
Similarly, Krosp is a dear friend on her world. He was created about two years ago, and as soon as he was rejected as a bad idea she adopted him as a pet, when he was still a kitten. As a result, the Krosp of her world is a much friendlier critter, and understands quite well that he is the pet and she is in charge. She instinctively pets him -- he tends to spend much of his time in her lap.
Gil is, of course, her foster brother and lover. They hadn't actually consummated the relationship, but had gotten to the point of realizing that they were deeply in love, and were preparing to tell Klaus when it all went bad. They realized that they were in love shortly after he came home from Paris, and were very engaged when it all went to hell six months later. She knows of Gil's parentage, and in fact knew Zeetha briefly: she had just come to Castle Wulfenbach when it all went pear-shaped, and was killed holding off the Geister attack almost single-handedly. She didn't know Zeetha well, but feels that she owes her a great debt, and has been trying to establish good relations with Skifander ever since. (With modest success -- with Zeetha, Klaus and Gil all dead, the Skifandese are understandably suspicious.)
She does know about the Suspected Revenant plot, at least loosely: she knows that Hive Engines were being built by the Geisterdamen before she crushed them, and that they were constructed using parts from Castle Wulfenbach. She found out that there were new Revenants that could pass as ordinary humans, and had developed her own version of the Revenant Weasels, rooting them out throughout the Castle. She suspects that Theo is a Revenant, and in this case she is correct: he was one of the early victims of the Spark-infesting wasps.
She does not know Dingbot Prime. In her world, she simply never developed Agatha's peculiar facility for Dingbots, which is a side-effect of her slow development. Mirror-Agatha is much more about offensive weaponry, which she builds faster and better than anyone else.
All of the Hostage Squad are known to her, and her relationship to them is very similar to Gil's in the mainline world. When she was younger, he closest friend was Sleipnir, especially when she was in her troublemaker phase around 13-15. But nowadays, she is much closer to Z and Zulenna. Both have been released as hostages. Z is her ambassador from his father, and that relationship has wound up strong. Zulenna helped her through the difficult days during and after she had to kill the Wulfenbachs, and is now essentially acting as her prime minister and closest advisor. She deeply respects Zulenna's intelligence, and her cold-eyed understanding of reality and duty. She is probably Agatha's closest day-to-day confidant today.
Meanwhile, Sleipnir and Theo have become two of her worst enemies. She rationalizes Theo as simply being jealous of her throne and wanting to take it over, but she knows perfectly well that they just don't like what she's doing. He has been working to subvert Othar against her, and she knows that he will have to be killed soon. Von Pinn went with them, which was the bitterest pill to swallow, since she had thought of her as a bit of a surrogate mother before then.
Wooster was the same as in her world as in this one. However, Gil never told her that he was a spy, and she was so alone after having to kill him, that they briefly became lovers, and he still serves her, apparently loyally. Her feelings for him are essentially deep friendship -- he is her best confidant. In fact, he has been steering her conquests away from Britain, making sure that his peoples' interests are well-protected. In the past year, she has officially had him appointed ambassador to her court, so his role as spy has essentially ended anyway.
Beetle is long-dead in her world, killed when the Geisters attacked Beetleburg to try to capture her when she was still a child. Silas is instead the head of TPU, and he is a much nicer person in this world. Agatha came to TPU shortly after Gil left for Paris, looking for solutions to the Brigadoon Effect, and she wound up having Silas as her mentor and close friend. She also knows Hugo well, although she isn't as close to him -- he is second-in-command of the University. She also knows Payne moderately well: he is the town administrator for Beetleburg. She's always felt that he didn't like her, and relations with Beetleburg have been tense in the past couple of years as a result, but she has never known why.
Think carefully about these relationships. Mirror-Agatha should actually know a lot -- all colored by the variations between the worlds, but she should probably know more about more peoples' plots than anyone else.
Characters In Game: Baroness Beetle DuPree Gil Jenka Krosp Othar Sleipnir Theo Von Pinn Wooster Z Zulenna
All Characters: Baroness Beetle DuPree Gil Jenka Krosp Othar Sleipnir Theo Von Pinn Wooster Z Zulenna