Well they do have a small air force (currently I believe about 65-70 operational) Horents currently. In your time line whether they actually got the F-35, went with the Grippen (heck bought SU-29's with the way that's been going), that would of course be up to the author smile I would expect Canada to go in heavily on drones. Cheaper, less man power intensive, basing is much less an issue, and long loiter times pretty all make an ideal package for what Canada has repeatedly stated are her Air Forces core goals of border security. So while they may not be able to bring the hate like the US, I'd certainly say they would present a major military consideration for the Russians if they're discussing a land invasion of Alaska.
Drones remove the human equation from the battle (in terms of your own losses). If the US is literally flying drones across the border to replace any Canada looses (with the latest upgrades and tech for free), there isn't a huge down side to "helping repel the unprecedented act of aggression launched against it's staunch ally and close friend the United States." Also the timeline for a full military response from Canada is going to be extended, but unless there has been a big change in US Canadian relationships I'd expect something with a maple leave being in the air flying in support pretty soon after this kicks off. In defense of St. Lawrence Island, eh probably not right away. However the second the Russians start advancing across Alaska, what is the reasonable expectation of the Canadians on where the Russians are going to stop?

Now if the Russian's have been up to some political wrangling, etc, they may be able to neutralize/forestall a Canadian response, but I don't think the characters presented so far would be in the know of that.

So if this is all already plotted, carry on smile

Oh one additional point, Bunny for a call-sign is pretty stereotypical. How about something like BWAS (pronounces boss). Politely it's Bad-A** With A Stick, though everyone she's flown with knows it's actually B**ch With a Stick due to her penchant for calling people out who screw up.

Overall good fun read, I'm enjoying it!

-Jenrick