If you have joint bank account - try giving evidence of that. Also you can get the marriage registered - takes 30 days approx. Also, explain to them why Aadhar DOB is not matching.
isnt the passport copy where the spouse names are entered sufficient as an evidence . In indian scenario marriage certificates were never done with until couple of decades ago.
could be other evidence just as joint bank accounts or opening bank account as name of primary account holder saying wife of xxxx
aadhar card copy explaining why error is there or else you can rectify that error - online or visiting centre.
sorry if i am not able to be crisp in my response, just trying to help by giving some random solutions but IRCC I hope considers all this and accept your application
if I were in your place I would add all above and include letter of explanation as to why marriage certificate not included. I am sure many indian parents have gone by this process and IRCC officials must be used to seeing such situations,