Hello,

Congratulations on getting the referral! To answer your questions -

1. If you think there's a chance you could get someone more senior to refer you soon (i.e. you are talking to them and think you can get the referral within a few weeks), I would say go for it, but otherwise a referral is a referral. Once you have the link, you can go ahead and apply. I don't think you necessarily need a more senior person's referral if you already have someone willing to refer you. That being said, is the office that she works in one of the offices you were interested in? That could be helpful for getting an interview if so.

2. As Ian mentioned, you can typically select 3 offices you are interested in. The immigration process can be quite tricky though. Once you have the referral, I highly recommend reaching out to a recruiter and ask to be put in touch with someone in their immigration team (for US and for Canada) to better understand the feasibility of getting a Visa. Having more insight into this process is crucial as it is definitely easier getting a work Visa in some countries than in others.