AITA for taking the attention from my colleague?

Hello, first time posting here. English is not my native language. I live on an island in the Caribbean.

Yesterday at work I was talking to some colleagues in the teacher lounge. I asked X why she was so quiet today, she said it was the anniversary of her son’s death, he passed away 13 years ago. We asked why she didn’t take the day off, she said she needed to be around people, needed the distraction, she needed to be busy. Her other son lives abroad, her husband, passed away 8 years ago. Her parents and sister are gone.

She was telling us about her son and how he passed away. His brother couldn’t take it, they were really close, so he moved abroad. They are still in contact, she goes to visit as much as she can. She mentioned that sometimes when buying presents from her son, she sometimes buys two, forgetting one son isn’t here anymore. But she still can’t get used to the fact she now only has one boy.

I said, I can’t imagine what you are going through, but I think I can understand. I have two daughters, and even though they have a seven year’s difference, I can’t imagine myself being the mother of just one child anymore. She said, yes, that’s it.

After school another colleague called and told me I was selfish for talking the attention from X. I should have let her talk and not try to make it about me. That everyone was quiet so she could unload and I ruined it. I feel really guilty now. Am I the A?

Edit: I talked to my colleague X today. She thank me for listening, she has been going around thanking us all. She told us she will be retiring at the end of the school year, early retirement.

Thank you all for your reactions.