Missing key elements.
Is your auntie a Permenant resident?
If so, then she needs to declare that she is not a US person and provide proof of address with her name on it. Yes she can use your address but again her name needs to be on it and needs to be within last 3 months. Change the utilities to her name or get her a mobile phone plan.
HK checks only work in Hk.
Hk banks offer HKD, RMB and USD checks. But they must be deposited into a HK bank. If you pay someone in Canada with a HK check. They will be pissed off.
I think some exception that you can deposit US bank USD checks in Hk but I'm not sure. There will be a fee and it's just better to wire the money.
Never heard of Canadian checkbooks in Hk.
Open a mobile phone w her name, open HSBC premier. Have them open a premier in canada. Easy to move funds. Don't use checks.