Get marry, dont worry.
Get marry. When you get file #. Send them marriage certificate against that file#. At the time of Interview, care will be taken of.
In my case, I got married after filing. I sent marriage certificate them. Even I got baby. I sent them that info too. But later I moved to USA (from India). they asked me do up-to-date application.
But in your case, if you are in same country. Dont woory. Just send them marriage certificate.
Landing fee for your wife, you can submit after interview also.