How long does it take for a Russian wife to get a visa to China?

Forever. Getting married in China means long-term residence and requires a permanent visa. The permanent visa for Russians to go to China is about $50. Visa is a kind of license issued by a government agency of a country to foreigners who apply for entry, exit or transit according to the laws of that country. The visa is usually attached to the passport or other international travel documents held by the applicant.