hi there,
i'm sorry i can't help you with your question about getting your mom to canada as i'm trying to get my Zimbabwean partner to canada too!!!! all i can say is to talk to as many people as you can and don't trust what the people on the toll free CIC phone line tell you. i've called them numerous times with the same questions and received different answers each time! forums such as this are much more helpful or speak with an immigration lawyer or consultant.
can i be selfish for a minute and ask if you are zimbabwean and when did you come to canada? how did you come here (work visa, temp. permit, family class?). i'm trying to get all of the info i can about zimbabweans coming to canada.
good luck with everything. i wish you the best.
canuck.