Yes, she can apply for a TRV first and then after she's in Canada send in an application to change status and ask for an open work permit as the spouse of a student.
Hi, I also recommend this option. My cousin who is a student was in your same exact situation and she and her common law partner were able to secure work permit for the latter already while in Canada.
I do not suggest that your spouse applies for work permit right away. CIC might wonder why she did not apply for work permit from Russia before she left. And she wait maybe 2 months so that it appears like she changed her mind after she got here. Applying right away means that even before she left Russia, she already had intention to work in Canada.
But nothing will stop you from applying right away if that is what you want to do and you can justify to CIC (only in case they ask) why you did not have her apply in Russia before you left. I am just playing on the safe side. But really, you can apply right away if that's what you prefer.
Good luck.