AITA for asking my sister/roommate if she wants to stay in our house or sell it?

My sister (29F, "Liz"), her girlfriend (29?F, "Vanna"), and myself (34M) have been living together in a house in northern Virginia that my sister and I purchased together a couple years ago. Both my sister and I are on the mortgage and deed. The intention was not for this to be our "forever" home, merely a way for us to avoid throwing our money in the black hole that is the rental market in the US. We both want to start families, separately.

It's been a dream of mine to build a custom house of my own. I have begun searching for land to build upon. In March 2024, I told Liz that I was looking to purchase land and build in early 2025, and that I would be moving out shortly after that. I advised her of the research that I had done on how to wind up our mortgage, and presented her the options I had researched: have Vanna and Liz refinance the mortgage in their names and pay me half of the equity we've built since 2021, or just sell the house and split the proceeds after the mortgage is paid. At that point Liz said the conversation was too stressful, and asked to "put a pin in it." Figuring she had plenty of time to come to a decision, I stopped bothering her about it for a couple months.

In June 2024, Liz and Vanna began trying for a child. Liz has been extremely stressed by the whole ordeal-- she is a trans woman who has not medically transitioned, and is trying to sire a child with Vanna. Both of them have extensive medical histories, and pregnancy would be risky.

It seemed to me like Liz was settling on a direction for her life, so on 1 September I approached her again, reminded her of her options, and asked her for her thoughts. Again, she told me that the conversation was too stressful and she was not ready for it yet.

At this point I realized that I was going to need to start documenting these conversations-- I felt like Liv was saying whatever she had to to put off having to make a decision about the house, so I would have to keep paying my share of the mortgage (which is currently split into thirds between Liz, Vanna, and myself, though only Liz and I are on the deed). I don't think it's fair to expect me to put my life on hold so I can continue to finance her future. So we had the following conversation via text:

Me: I understand that thinking about money and moving (or staying) is stressful, but I am worried that you are going to be blindsided when I move out. I want this to be as easy and painless as possible for both of us, but in order for that to happen we have to actually make a plan of attack. I have tried to have this conversation a couple times now, but each time it's too stressful or upsetting. Can we please pick a calendar date to actually have this discussion? Or a date by which you plan to make a decision about whether you are going to stay here or move? Figuring that out impacts the money that I will have available for my own move and purchase.

Liz: hey sorry, it’s not your timeline that makes me anxious. we’re aware of that and planning around it. it’s that our entire lives could change forever at any moment once Savanna gets pregnant, so we literally just don’t have any idea what stage we’ll be having to make the decision in. that’s all, i’m not upset or mad or anything, just general anxiety about so many unknowns on our personal end of that

Me: They don't have to be unknowns if you think through and plan out how you want your life to look. Make 5 year and 10 year goals.

Me: It's none of my business how you and [Vanna] choose to start your family, but it strikes me that now might not be a great time since I will be moving out around the time you all are expecting the arrival of the most expensive investment of your lives.

Me: It sucks that multiple stressful things might happen at the same time, but avoiding thinking about them isn't going to make them go away

Liz: it makes me feel anxious when someone else is in a place to talk about a topic and i feel like i don’t have a way to not engage in the moment because i don’t want to be rude, but it’s just not a good time for me to be thinking about it. it’s not the topic, it’s all of our added considerations that you’ll just never have to be concerned with. this is anxiety over life as a parent, not about money

Me: You're right. I'm never going to have the opportunity to be concerned about having a child, because that option was taken from me.

Me: Also that was pretty fucked up

Me: That really sucked to read from you

Liz: That's not what I meant, I'm sorry. I'm just trying to get across that there's a lot more I need to be thinking about right now.

Liz: It's a triggering topic for me right now, and I'm just not in the mental state to handle it right now even if you are. What I was trying to say is you're not going to have to figure out how to juggle a pregnant partner or newborn at the same time as moving. I'm not trying to rub anything in your face, I don't have any evil agenda to hurt [Skelattorney]. But this is triggering and forcing the topic and conversation to continue after I expressed that is intentionally triggering. If it continues I have no choice but to assume your intent is malicious and I will block you if you cannot respect someone's basic boundaries. I will not allow myself to be triggered into panic attacks by anyone.

I have not spoken to or texted Liz since I received that message. I moved out my necessary belongings (work computer, medical equipment, clothes) back home with my parents. I am still paying my share of the mortgage, but I am not interested in resuming living with them. My mom thinks I should be the bigger person and reach out to her, but she literally told me that if I try to talk to her about this again she's going to block me. Liz has been complaining to our parents that I'm throwing a "tantrum" and refusing to communicate. So am I the asshole for asking my sister whether she wants to stay in the house or sell it?