I'm getting too emotionally invested in @gonzague-if that I've decided to go develope Headcanons about my Prince Médée's family. I've even come up with concept designs and created a family tree charting their relationship dynamics with each other.
I've given Médée's younger brother Philippe the full name of Gonzague from the Le Bossu novel to tell him apart from his sister. Also, I headcanon if little Philippe had survived to adulthood, he would look very much like the novel version Gonzague. Despite the fact Philippe was on the track to turning into an abusive POS like his father, I headcanon Médée didn't actually want him to die. They probably got along when they were young children considering how close in age they were, but Médée is probably the only one old enough to remember those times. Also, even with Philippe being their father's favorite and heir doesn't necessarily mean he was free from his father's abuse. Philippe had to learn that behavior somewhere, and I wouldn't be surprised if the former Prince used harsh corporal punishment on his heir if the boy showed weakness, even if Philippe wasn't punished as often as Médée. Also, considering their father was a firm believer in only the strong survive, I wouldn't be surprised if he pitted his own children against each other to see which is stronger. Médée figured out early on that her father sees her and her brother more as valuable chess pieces rather than his children, so she doesn't care about winning his approval, she just tries to succeed just enough to avoid punishment. Philippe, however, was still young enough to care about his father's opinion. So he gets very jealous and angry when his bastard half-sister gets praised by his father for being clever when she gets better marks on their arithmetic studies, or when the girl he has a crush seems more interested in spending time with his older sister because Médée is the "cool fashionable teenager," while Philippe is still at that awkward preteen phase and bigger than most of the other kids. So he lashes out at his sister physically because acknowledging his emotions and insecurities is weakness.
Considering the previous Prince of Gonzague, didn't seem to grieve the death of his only son but instead made Médée his heir by forcing her to literally replace her brother, even giving her Philippe's name and raising her as a boy. It is safe to assume he was an absolute bastard. Which seemed fitting considering out of his children his illegitimate daughter is the one who physically resembles him the most. Médée inherited his nose, square face shape, and height. While Philippe had his father's dark curly hair and eyes, he had softer features and a rounder face like his mother. Médée despises the fact that she looks so much like him, even long after her father's death. Even though she inherited her blonde wavy hair from her mother, it started darkening as she got older. So Médée will often have Peyrolles help her lighten her hair regularly. Most people at court assume it's just for fashion since blonde hair was in vogue at the time. In reality Médée does it because she hates how much she is forcefully reminded of her father whenever she catches a glimpse of her reflection with darker hair, especially when wearing suits. He's dead now she made damn sure of it! Her father can no longer hurt her or control her life again!
It probably shouldn't have surprised Médée that her father was also controlling with her birth mother as well, a fact she didn't learn until after her father's death when she found some letters in her father's personal effects. Until then Médée never knew anything about her mother, except that she inherited her eye and hair color from her. Apparently, her birth mother was a Mezzo-soprano opera singer from Vienna named Laura, whom her father became enamored with after watching her perform Dafne for the court in Mantua during his youth. It seems that despite the fact her father despised "weakness," he was also a hypocrite, considering how pathetically in love he was with her mother from his letters. Especially since from her mother's responses Médée could figure out her mother was politely indifferent at best to her father's affections before gradually starting to resent and despise him. Considering how competitive the theater can be, actors and opera singers can be just as scheming and cut throat as the nobility at Versailles, except their poisoning and assination attempts are usually only on stage. Apparently Médée likely inherited her cunning and charisma from her birth mother as the Austrian Prima Donna earned her spot not just for her musical talents but also knowing how to plot and recruit alliances to get ahead. Unfortunately, Laura's ambitions to secure a Nobleman sugar daddy backfired, and she wound up with a possessive and controlling Baby Daddy instead. If the Prince's attempts to woo his golden haired songbird wouldn't make her love him, he has other means to get her to agree to become his mistress. His title and influence give him enough strength to threaten to ruin Laura's career she tries to leave him, and being unable to outright rejects the Prince for fear of her lively hood...well an unplanned pregnancy would shackle her to him as well as any chains. Her mother does eventually escape her father and flee the country but unfortunately had to leave baby Médée behind. Early in her opera career Médée's mother was often cast in "breech roles," where a female performer would play a male character, which not only seems to be a trait Médée inherited but helped her avoid being found after fleeing the county.
As for the late Princesse de Gonzague, we unfortunately don't know much about her other than she was a gambling addict and died shortly after giving birth to her son (although considering how Médée's father was it's a reasonable suspicion that his wife didn't die from complications from child birth like most people assume). It can be safe guess she was not happy being married to such an awful man, and like most noble women from this time period, she probably left the raising and care for young Médée to a nurse or nanny. I do headcanon that Médée's stepmother also had lighter hair, partly because it would be easier for her father to pass her off as Philippe if his wife had a similar hair color. Also, I think it's funny if Médée's father had a fondness towards beautiful blonde women, but they always wind up hating him😂.