Because she did not reveal her relationship with me when applying for her first visa, is this likely to be intrepreted as deception by the visa officer?
I don't think so. When I applied for the first time for a visitor visa, I only wrote in the form that I was planning to visit Vancouver for 15 days and then go back to the US. Visa approved. At the Port of Entry I said I was going to stay in Vancouver for 15 days and would visit a friend. After many questions, I was given 6 months to stay, but left after 15 days.
Second time I applied, we were already married. Again, visa approved, with no problems. At the Port of Entry I was only asked when did we get married (it was not during my trip to Canada) and I received 6 months to stay.
Is she likely to be refused the visa now that we are legally married?
I didn't have any problems. But our visa offices are not the same.