Am I expecting too much from my partner’s 18-year-old daughter, or is this just basic respect?

I’m 38F, no children. My partner is 38M and has an 18-year-old daughter. We’ve been together for four years and our relationship is genuinely great most of the time. I almost never think about leaving him — except when his daughter visits.
She actually comes very rarely, maybe once a year, which makes me feel terrible about how much I dread her visits. I keep thinking I should be able to tolerate a few days for the man I love. But after four years of accumulated incidents, I’ve developed so much resentment that everything she does irritates me now — even her perfume. Sometimes I can barely look at her, and I feel awful about it.
The problem is that what I originally wanted was very simple: basic manners and to be acknowledged as a person in my own home.
Over the years, I’ve had to ask my partner to teach her to say “good morning” and “thank you.” I’ve had to explain that if there are three snacks for three people, she shouldn’t eat all three, and that if she asks me to buy her food, she shouldn’t leave the empty packages around the house.
She has also been incredibly disrespectful to me in the past — calling me a fool, sarcastically asking if I was three years old, and once telling her mother that a vape found among her belongings was mine. My partner never really corrected those behaviors at the time.
This visit, she left food and crumbs on the sofa, spilled ice cream by the sink and left it until there were ants, and when told to clean these things, basically removed the obvious mess without actually wiping anything down. She plays things loudly on her phone and sings loudly without considering anyone else in the house. She lies across the entire sofa using my blanket; at one point I walked into the living room with nowhere to sit, my partner gave me his seat, and she remained stretched out.
There is also almost no independence. She can’t walk alone to the beach 200 meters from our house or navigate the subway by herself. She has repeated two school years because of absences, yet missing another school day because transportation wasn’t planned doesn’t seem to concern her parents much.
This weekend my partner drove to pick her up because the only bus left was at 11 p.m. When I questioned why an 18-year-old couldn’t have planned and bought her ticket online earlier, he told me that whenever something involves his daughter, I create a problem.
Then he planned to use my Monday trip to São Paulo for a medical appointment to take her home because she can’t navigate the subway alone. I’m currently dealing with serious health issues, significant pain, medical tests and a potentially urgent surgery. Taking her home afterward would mean losing basically my entire workday.
I initially said okay because I always feel cornered when it involves her. Eventually I decided I wasn’t going and would reschedule my appointment. He offered several alternatives because, to be fair, he didn’t want me to miss my medical appointment. But at that point I simply didn’t want another day traveling with her. If he wants to drive his daughter home, that’s completely fine — I just don’t want my medical appointment and workday to become part of that logistics.
I know I’m no longer neutral about her. Four years of resentment have accumulated, and I’m sure some things irritate me now simply because it’s her. I recognize that, and I genuinely feel bad for my partner.
But whenever I ask for boundaries, he interprets it as “you don’t want my daughter here.”
I have never told him she couldn’t come. I’ve never asked him to choose between us. But the horrible irony is that, after years of this, I now do dread having her here.
And it is affecting our relationship. When she isn’t here, I love our life together. When she visits, I become so angry and uncomfortable in my own home that I think about leaving him.
Am I really expecting too much from an 18-year-old by asking her to greet people, say thank you, clean up after herself, respect shared spaces, not insult me, and develop some basic independence?
Since she only comes once a year, should I just tolerate it for my partner’s sake?
And how do I ask to simply be acknowledged and respected as a person in my own home without automatically becoming “the evil stepmother who doesn’t want his daughter here”?
Because that’s never what I wanted. But after four years of this, I’m afraid the resentment is turning it into exactly that.