I can't remember exactly. But I do believe we got the Marriage certificate within 4-6 weeks after getting married. Apply now if I was you.
Don't think I read on here, sure it's still a requirement. She will need a TB test.
I didn't know about the TB test, although I suppose it makes sense. How does she do this and when? Is it done before or after the visa application? If before I assume the certificate needs to be presented in the packet? Are there any other medical tests she needs to take?