Struggling with models in conjunction with boundaries

A boundary is not trying to change another’s behavior, it’s stating that there will be a consequence that I will follow through on if they continue the behavior/action “in my house” that affects me emotionally or physically.
Scenario: My sister and I (and my excited 11 y.o. nephew!) plan to have my nephew come visit me across the country for a week, his first big trip. After a year of talking about this, him nagging both me and my sister to buy tix and us planning it, the date is set.
I carve out a week of my time, take off work and plan a week of activities for his visit (which include plans with friends and their kids). My sister and husband fly out with him, drop him off and are supposed to go to Vancouver BC (I live in Portland) but they decide to stay close by for 3 days before heading north. After only one night of him staying at my house solo (my sister stayed with him the first night) he called my sister that evening and the next morning crying saying he was having a great time (we did tons of fun stuff) but missed them so much. I explained to him that feeling homesick was totally normal but he was safe with his Auntie and that his mom was only a phone call away. Without having any conversation with me, my sister decided to let my nephew end his stay with me and go with them. I think the thing that was most difficult was that not only was I was not part of the conversation, I had carved out a week of my time, made plans and taken off work for my rad nephew (whom I was excited to hang with since I rarely see him as I live across country)

I haven’t talked with her about this, but she could tell I was super disappointed.

C: Sister took nephew 6 days early. I do not get to spend time with my nephew.
T: Sister does not consider me, my time, my thoughts.
F: Hurt, Disappointed
A: Detach from her
R: Very little contact with family and unwillingness to make plans with her

Is the result the consequence moving forward? If people can’t honor your time, shouldn’t there be a consequence?

My instinct is to go through this model with her so she can understand where I’m coming from.
alternate model
C: Sister took nephew 6 days early. I do not get to spend time with my nephew.
T: My sister is a pushover and this has nothing to do with me
F: bummer
A: tell her that it’s a bummer
R: ???