Do I have to restart a friendship because we will both be at the reunion?

The reunion organiser messaged me: "I've put you and Mara on the same table. You used to be inseparable!" We haven't spoken for nine months. Before telling a wider group that I was leaving my job, I told Mara and asked her to keep it to herself. She mentioned it in our group chat that evening.

She apologised when I called her. I believe she forgot rather than meant to hurt me. But I had spent the next day explaining a decision I hadn't been ready to discuss, and I stopped telling her much after that. Neither of us followed up after a stiff coffee.

Now she has sent, "Would be lovely to have a proper catch-up at the reunion." I don't want to spend the evening pretending we never fell out. I also don't want the organiser or everyone at our table dragged into it. Mara's message may be a real attempt to reconnect, and I don't want to punish her forever for one mistake.

Can I be friendly that night without agreeing to be close again? Or do I owe her a separate conversation before we sit at the same table?