Moving to Canada - how to sponsor my girlfriend - not living together?

[astaron]

Hi Everybody,
I have been in contact with a Canadian company in Toronto, who may hire me permanently and sponsor me for my working Visa.

They told me they may be able to sponsor my girfrieng too.
They are aware she is NOT living together with me and that we are NOT married yet, but they said they may handle it, somehow.
According to the recruiter, there may be a way to let her have an Open Work Permit that may be valid as long as my contract is valid and I keep having my sponsor.

My question is: how do I prove that me and my girlfriend are, infact, a real couple and not a fraud?
I am afraid that proving we are together may become an issue to get a visa for her.

I am British Citizen with British and Italian passport and she is French (she doesn't do the same job as me).

Can you help me sorting this out, please?