Advice Brussels with a 77-Year-Old Mother

I'm planning a special trip to celebrate my mother's 77th birthday in May 2025, starting with Paris and then heading to Brussels. I'm looking for advice on making Brussels enjoyable and comfortable for her. She loves history, art, and good food but isn't up for too much walking. Any recommendations on must-see attractions that are senior-friendly, cozy cafes, or any tips for navigating the city with an elderly parent? Also, if there are any specific areas or accommodations that would be ideal for us, I'd love to hear about them.