I am sure the girls on the site can give a better answer than I can.
But there will be different categories of responses from the girls:
1. You should definitely do it. And some people will mention how they have known older or married people Rushing/pledging/joining.
2. You need to understand that Rush can be very competitive at southern Schools so being married can count against you.
3. Sororities can be pretty time demanding, and you have outside committments that might prevent you from giving the sorority the time it demands.
I am sure there will be questions also:
1. Why do you want to join?
2. What school do you go to?
ETC.
Personally: I say go for it! And don't let anyone talk you out of it 
Also, I see no reason you need to mention that you are married during Rush . . . ITs not like its going to come up during conversation lol 