What should I do? (About a friend)

So I just called one of my best friends to see if she wanted to get together  and she blocked my number. I know what your thinking she must not like you. But We just hung out like 2 months ago and everything was fine. The only thing is I seen her husband having dinner with another female and I told her about it. And she didn't believe me I had no reason to lie. I really want to remain friends? Should I have not told her what I seen? What should I do? Any advice?