Kids will learn another language almost by osmosis, if in immersion outside the family, but even if you are a polyglot , your own kids might resist learning from you, a language other than the one the family uses day to day. Wt asked the Special pioneers, at one time to speak the language of their assignment at home, what a disaster, how do you let your hair down in another tongue?
taking your kids, wife to a foreign language congregation is a good idea, Chinese preferred, they will not get a thing out of the meetings for a long time, and that is a good thing.