Ex asking if you’re “really happy?”

When I was engaged to my now husband, his ex girlfriend from college started messaging him again. He said they’d remained friends after she ended things (I can understand, as she literally saved his life when he was drowning in a river). They wrote to say hey to each other every once in awhile. He always shared with me what they said to each other. I didn’t ask to see, he just wanted to be transparent.

He sent a picture of him and I to her. She seemed a little upset, maybe even jealous, and then asked him, “Are you really happy?” He responded, “Yes, very happy.”

I was disturbed by this question, and asked him to block her. I was fine with them being friends until she asked that question. It seemed like she was trying to get him back. He agreed and blocked her.

Now I’m wondering if I interpreted it wrong? Was I too harsh? What would you think if you put yourself in this situation?