How to react?

Just talked to an elderly neighbour who I haven't seen for a few years. She used to talk incessantly about cats. But today this:
"My husband died on the first of the month ..."
"Oh I'm sorry ..."
"He wasn't ill. No. He had high blood pressure inside his heart and it crumbled his heart from inside and he had a cardiac arrest. I took him in his coffee on Tuesday and there he was. Funeral on Friday. Two and a half grand."
And she walked away.