AITA for saying no to hosting a charity art show?

This happened a few months ago but I still think about it from time to time so I thought I’d post here. I (33f) met Diane (38f) a few years ago in my city. She is an activist and I run a small art space. Over the past couple years, Diane and I had basically done a mutual slow-fade. To be transparent, she had a child and I wasn’t really there for her because I was carrying some resentment about some past treatment, but I did message her congratulations (she never responded). Though the art space wasn’t doing too well, we won a grant to put on a show that had some significant social media promotion. One day in the middle of this, completely out of the blue, Diane messages me telling me all about a really good cause she is leading, and asking if we can do an art show to raise funds.

I’ve had a rough couple years. My father died suddenly last year and this year I ended my six-year relationship. I posted on social media about my father’s death and Diane’s reaction was *crickets*. It honestly really annoyed me that she came out of the woodwork to ask for such a big favor after not even bothering to send one message about this life-changing and tragic event in my life. The art space is not doing too well either, and we’ll be closing early next year. The reason I pulled away from Diane is because she had a tendency to be really bitey and rude, and I simply did not want to invest in a friendship where I was walking on eggshells all the time.

Knowing this, and feeling really exhausted from doing art shows, I simply messaged her “Hi Diane, our schedule is full but good luck with that.” She responded along the lines of “Good luck with that?” and outlining the severity of the cause before blocking me. I messaged her on a different platform: “Hi, I saw you blocked me but just so we’re clear, here’s my last message. Look Diane, my Dad died last year and I didn’t even get a single message from you. You don’t know anything about my political practices because we don’t talk and you don’t know anything about my life. The truth is I’m not interested in working with you because I think you’re a difficult person who enjoys conflict, and I think your political praxis is extremely performative. I hope your show goes well and I hope you get it clear in your mind that I owe you absolutely nothing.”

To be clear, I support her cause. I said no because I just didn’t want to do any more art shows, I don’t believe we could raise a lot of money, and I especially don’t want to work with her. This is somebody who will go off on you for the smallest infraction, and in her message she didn’t even say anything about the cost of upkeep for the space, she just felt entitled to free labor. I know I wasn’t a good friend when she had her baby, and I know this was for a good cause, but I still think I have a right to say no. So, am I the asshole?