Setting a healthy boundary does not mean you don’t also love them.
I left home at 18 and haven’t lived within 800 miles of my parents since. I call them every week and spend time talking about things that don’t upset either of us. We have plenty in common. I visit several times a year. We tell each other that we love each other all the time and when emergencies happened over the years I showed up and handed things. But when my parents and siblings tell me that I should consider going back to college “just in case” so I “have something to fall back on” I gently remind them that I’ve been self employed for the last 25 years, most of that was semi retirement and at 51 I’m financially independent and will never have to rely on anyone for my paycheck. They simply can’t grasp the concept. “How can you own a business in another state, never go there and still get a paycheck?” “You’re not working, how are you getting paid?”
I don’t call them “wage slaves” or “tax cattle” I don’t try to wake them up to the fact that they are pawns in a 150 year old government psyop. Living outside the system would be too much of a shock for them. I simply offer to teach them if they want to learn. When they say yes, I don’t try to explain anything. I tell them to get a hard copy of Thomas Sowell’s “Basic Economics” and read ten pages at sunrise every morning with their bare feet on the grass before looking at any screens.
“Can’t you just tell me?” No, putting in the work and going through the process is what gets you there. We can talk about it more once you’ve completed the first steps.
No one has ever bought the book and you can’t make them. Giving them an assignment ends the conversation peacefully and opens the door for other topics.
They will wake up when they are ready and there is nothing you can do to change that except share love and be successful on your own path. Family is the core of one’s community and it sounds like you and your sister would be there for each other in an emergency, don’t ruin that, you don’t have the resources to overcome all the brainwashing that’s out there. Nurture what you have and let the rest go.