Meaning?

Hi, what is the meaning of "I stood for emotionalism " and " to pick my moments " in the following text?

" I tried not to talk about it all the time." Ann said in a deposition some years later. " I knew how I was being received by my husband. I stood for emotionalism; I was the hysterical mother. With Dr. Truman, I'd try to pick my moments. He was always very patient.

Please note that Ann is the mother of a child who has leukemia and she is all the time talking about that.

Thanks