I don‘t think skating abroad is even a serious option for Polina. I mean, training abroad doesn‘t only require to move country, part of the family has to move as well, maybe even giving up the job as a result. (I always wondered about that: How did Zhenya‘s mom do that? Is she working in Toronto or has she gone back to Russia?) There‘s also a language barrier and most skaters I have seen so far don‘t speak English well and neither do their families. I know Zhenya said in an interview her mom can‘t really speak English. So how are you going to do that as a non-top skater without real support from the fed? Even as a rich family it involves a lot of struggles and problems to consider even though the main point - money - isn‘t an issue for them. Evgenia‘s situation was highly unique and I don‘t think the fed would allow it for just everyone - probably only top skaters which Polina sadly isn‘t.
Family usually cannot go, since you cant simply move to a foreign country and live there. Visa issues and all.
I mean, check on Javier or Lizbet and their own and their family visa issues.
Overall, I do not see any possibility of Zhenya's mom staying in Canada for more than a few months. For a longer stay, she would need Zhenya to have canadian citizenship, or get a job in canada (which is not trivial for a non canadian, there are quite a few requirements). Stuff like that.