Female, the whole family invested and immigrated to Canada. When can they come back after they go out?

Come back anytime. But Canada has an immigration supervisor, that is, at the green card stage, you must abide by the requirement of living for two years within five years.

Of course, if you live in Canada for three years within four years and get a Canadian passport directly, you will no longer be restricted by the immigration director.

I suggest that if you want to return to China for a long time, try to get a Canadian passport!