Check her employer's medical coverage. Mine covers trips up to 21 days, others may be more generous. Also, check her credit card - if she buys the plane tickets on the card she may end up covered as a result of that.
To answer the second part of your question, what does Canadian health care provide, depends on your province - health care is a provincial thing. But to give you Ontario as an example, there is very rudimentary coverage. The online advice from the Ontario government says things like:
The Ontario Health Insurance Plan (OHIP) only covers emergency health
services at very limited rates. For example, an outpatient visit to a
U.S. emergency room may cost thousands of dollars for the duration of
your care, however OHIP will only reimburse up to a total of $50.00
CDN per day for this service regardless of the severity of the
situation. If you plan to travel outside of Ontario, it is strongly
recommended that you obtain additional private medical insurance and
fully understand what your policy covers.
That emphasis, by the way, is in the original. There is also a fact sheet which is even gloomier. I doubt the answer will be remarkably different if she lives in another province.