You were told something as close to dead wrong as Santa exists (sorry to those who think that).
She has to qualify to immigrate as a family class applicant to Canada, and they will make inquisitions as they see fit to determine if the marriage is a sham or fake. Which my Spidey-sense is telling me might just be the case here. It will take at least a year.
Note a man marrying a Dominican woman doesn't get DR citizenship either. Women do if marrying DR men, at least less hassle than normal.