Dear Rendezvous70,Rendezvous70 said:The only issue while applying for her visitor visa right now is that the embassy officials are apprehensive if your friend's mom may not come back and hence become a burden on Canadian economy. As they are aware that the son is going as an Immigrant and eventually will settle there.
Having a valid US multiple visa on the passport makes it much easier to get the Canadian visitor visa as Canadian Border services share their data with US homeland security and once the US visa is stamped on a passport it is a kind of US certification , which facilitates Canadian visa .
I suggest that your friend should reach Canada first and after couple of months his mom can apply for visitor visa. Once she travels to Canada few times on visitor visa, then you should apply for Super visa.
Lastly , if your friend wants to take his mom along now, he can take a chance to apply her visitor visa but I am quite sure the high commission will not give a long stay if at all they issue a visa .
Thanks for your opinion +1 for that.
Best Wishes.