MithuShun said://I hope that both you and your wife signed the invitation letter by saying you both be responsible for your mom.//
This is the mistake I done. I could have went through this thread before I submitting the documents. I mentioned everything in the supplementary attachment to let VO knows, which includes wife details and my children school name and grades. However, I did not ask my wife to sign.
As you said, I will gather the documents as much as I can and write a letter to VO. In case they rejects this time, at least I can correct at next time.
Finally, My mom got the super visa on last Friday and will be visiting to Canada in next couple of weeks
Thank you very much for this forum and great members. You guys helped me in many ways and in return, I will try my best to help others in this forum on super visa matters.
Cheers