Hello!
According to what you have described in your previous post http://www.canadavisa.com/canada-immigration-discussion-board/trv-for-me-and-my-son-please-help-t181328.0.html you have quite an extraordinary situation. Due to the fact, that in the past you were applying for immigration and have been refused, it will clearly be difficult for you to get TRV (you are "high-potential immigrant" for CIC). But that does not mean, that there is no chances at all. I think, it would be better, if you or your mother could consult a good immigration lawyer.
But in general, in your situation you have to make a special effort in showing the ties with your home country. Simply having a husband is not enough. There should be a compilation of the factors: good job, stable income (showing a big amount of money on your account without job would not work), property ownership, also good travel history (but it will take at least a few years to create one). Think what else can be presented as a proof that you will come back, maybe there is something else in your life?
When you will be applying again, write and attach a cover letter, explain your situation, declare that you understand the immigration rules and decision which has been made upon your case, that you do not have an immigration intension and you just want to see your mother and let her see her grandson. Give the details for the reasons which are keeping you in your home country and will make you to come back.
That s the only thing I can suggest. Good luck!