One thing that Ms B and I agreed to off the bat was the benefit in our child learning to read and write in Mandarin.
Ms B, like many Chinese, more commonly speaks a dialect of Chinese, but she and her mother have made an effort to speak only Mandarin in front of the child, so that he could pick up official Chinese without getting confused with the dialect.
As it stands, Master A, who is almost 7 years old, can read and write exceptionally well in English, and he can also speak moderately well in Mandarin. He goes to Chinese school twice a week and is slowly learning the numerous characters that comprise the Chinese language.
