And the daughter is Jiang. Is it related to Zhang Yaruo?

Jiang has nothing to do with Zhang Yaruo. It's just a coincidence that they have the same Chinese characters.

Jiang follows his brother's name and his son's name: Wen.

Plus, if Zhang Ya and I met after 1939, and Jiang was born in February of 1936, then he was still in the Soviet Union and returned to China on 1937.