Unless the Canadian girl will be living full time in Canada, she loses her medical benefits. Shouldn't be a problem though since I understand the UK has a comparable scheme, but this is a fact of life for those who do not continue to reside in Canada (and many say "good riddens")
Here is a good site regarding taxation. She may opt to file with the Canada Revenue Agency so that they themselves say that she is no longer a resident and have been notified (so they don't come chasing her for money later):
http://www.cra-arc.gc.ca/tax/nonresi.../nonres-e.html
(another "good riddens")