ok wtf is up with occtis's mom fr
alex deliberately didn't reveal anything in the fireside chat, and occtis ignored/deflected vaelus when she asked him in episode 3, despite being relatively open about his family stuff otherwise (although at that point he barely knew vaelus).
she has not been mentioned or present in any of the tachonis schemes or locations thus far, which could mean nothing. like nor have two of occtis's siblings, but her absence is more glaring because as primus's wife she would presumably be the lady of the house, and would be present at like the sundered house meeting, or generally involved in The Evil Plan.
stuff we can concievably assume:
she is from a different noble house, and doesn't have (at least tachonisy/necromantic) sorcerous ability. the tachonises, and explicitly primus, seem to not like poor people, given doset's interactions with casimir and primus's speech in e30, so I can't really picture papa p pulling an aranessa royce. nor do I think he would've been up for incest because of his dunking on petra and ryah (unless he was compensating). I guess she could have been from a vassal house, but the only tachonis vassal we've seen thus far is seremai, and they're all snaky, and primus's kids have an explicit lack of snakiness. and on that point if she had some other kind of sorcerous ability it didn't visibly transfer to any of her children, that we know of.
she was probably married to primus, was probably a woman, and probably had all 8 kids herself. this is all just because of the general strictness of nobility surrounding like courting and stuff, without having a specific alternative like king gus naming his nephew heir (but if it was something like that I feel like it would've been mentioned? but idk)
she was not particularly nice or warm to occtis. occtis has mentioned a lot how he's always been an outsider in his family, and recently that thimble and thaisha are the "two people that care about [him]", and alex said in the fireside chat that he was mostly raised by tutors and stuff. so either she was just as cold to him as the rest of his family or she was out of the picture for most of his childhood (and occtis isn't like. looking for her). also on a meta level brennan has been very good about making the women in his campaign like complex, and even maya who is very motherly in some ways, is not just the stereotypical tragically perfect kind loving mother who never gets mad etc, so I don't think occtis's mom is going to be that either (and I fucking love maya she's perfect but she's perfect because she is both a mother and a person). and alex explicitly said he didn't want occtis to be some inexplicable chosen one who always knew his family was horrible, so it wouldn't make sense for his mom to be that, either.
stuff I'm fully theorizing:
she's not dead. first of all, that would be boring, and second of all, the tachonises have like? control over the dead? like nullus is dead and he seems to be just kinda hanging out in the tenebral reaches, still very active (he showed up when occtis was dying, when spoke to tertia, and when they tried to speak to thjazi, and he always seemed like he. was totally in control). so her being dead wouldn't be an excuse for her to not be active as part of the Evil Plan or whatever (sidebar: I'm very curious what will happen to frons and koral now). she could totally be dead, but she would have to be dead AND excommunicated or some other bs idk.
she's not dame gaya seremai. ive seen this theory and I don't know if it makes sense for occtis to be an obvious bastard because that would have been like mentioned? like sure his family hates him but if anything they hate him because he has all the right blood and is still a disappointment. and gaya/any other affair woman wouldn't be a reason for him to not have sorcerous powers because those come from primus in the first place not his mom. so its possibly that he's a bastard through his father, ie his mother cheated with someone who isn't primus, but that still leaves us drawing a blank for like why she isn't around (unless that's what got her like shunned from the family? but again occtis was a bastard they would have just been like he's a bastard fuck that guy). so then we would just have two mystery people running around.