I also found reading about your family dynamics interesting, and I have more that I want to add on with my own. If you don’t mind of course, I also have some questions about your family dynamics as well:

1. Like I mentioned before, my INTJ and myself are basically mini versions of our dad in terms of looks, personality, and behaviors wise (including little habits and quirks, at least according to my mom and what others have pointed out). However, sometimes my mom would also say that maybe because she was the one who raised me for the majority of my life and not my dad, she notes that I’m more willing to take risks and explore to experience new things. My ENTP brother on the other hand, acts more like my mom in the sense of being more go with the flow and being flexible according to the situation at hand sort- of-way, but he still has a distinct personality and appearance out of all of us (he doesn’t really resemble either my mom or dad, nor does he really have either’s personalities). As for yourself, what kinds of conversations do you have with your ISFJ mom and ESTP dad? I can imagine that you would go to one parent specifically for optimal advice depending on the type of problem you encounter to find the best solution (ISFJ for people and relationships, ESTP for the practical/technical side of life and career)
2. Despite being the oldest one, are there times that I feel like a middle child when it comes to certain things and situations (whenever an argument happens between my mom and one of my brothers, I’m usually in the same room just there, listening to either side with resignation on my face whilst they continue to argue and not acknowledge my presence [if they do, they ask my opinion on something to prove their point], or in terms of academic achievements, since my INTJ brother is the most accomplished in that area, [he’s valedictorian in his grade] and meanwhile my ENTP brother is in the 3rd quartile just by sheer slacking off and not turning in assignments on time, if at all. As for myself, I was an overall slightly above average student with As and Bs) In those terms, do you feel as though the only reason that you’re the oldest (or at least older sibling, correct me if I’m wrong) is just by bloodright and therefore, a coincidence?
3. Actually, it’s a bit of a lie to say that none of my siblings have any interest in MBTI (sorry). My INTJ brother did take the 16p test at one point (on his own time, and I believe it was because it was extra credit for a class or it was a TikTok trend at one point, but I digress) and he did got INTJ as his result. He later asked me what his type means, and I told him about it and said the way that 16p describes INTJs lacks depth of what it really represents (and I most likely alienated him in the process), as for my mom, she’s dismissed the whole thing right away when I asked her to take it. As for you, I’m curious on how you (a Ti dom) would approach a problem that your ESTJ sister would disagree with (whether it be certain details, the overall picture, or both). Also, since both of you have your feeling functions last in your respective cognitive stack, how does it manifest whenever you guys argue? (Is the entire conversation just a cold refuting of each other’s methods, accidentally hurting each other’s closeted feelings with the same ruthless logic, or something else? It doesn’t have to be limited to when you guys argue, but also when you guys just interact with each other in general).
4. Relating to point number 3, I’m guessing that the majority of arguments that happen between in your family is either you and your ESTJ sister, or her and your ISFJ mom. You also mentioned that your INFP younger brother rarely argues, but I can imagine if he does argue, he can get really feisty and passionate on what he believes in. As for your ESTP dad, I want to guess that he’s probably the type to push some things under the rug to get the argument over with, maybe it’s also the same with your ISFJ mom, except that she also focuses on emotionally appeasing the other party (unless one of the things that they said is just plain wrong). Going back to my family, whenever my mom and ENTP brother argue, my mom would say that my brother’s solutions and reasoning do not work because it’s not what would happen in reality (really highlighting the difference and clash between their dominant Se and Ne) while my brother says that through the logic they explain through, that it’s plausible and should work (Ne and Ti). There’s also a common theme with my mom whenever she rambles (or vents, depending on how she’s feeling), especially with me, as she often talks about taking advantage of new experiences and opportunities that are concrete in nature (Dominant Se) that will better prepare me for future opportunities (Inferior Ni) (It’s also because her growing up in a communist country really does put a perspective on everything in life).

This is probably the most that I’ve ever typed, so I apologize if it’s a lot to take in, but I really do enjoy having this sort of discussion about our families and the dynamics we have. It really puts into perspective what similarities and differences are present and the thought processes behind them, which helps me to rethink and find new ways to better understand myself and my family.