[Sophia]

For Canada I don't think you can do much better than Piranha. In fact somebody in my family uses it now as their main cell phone. Reason is the top up requirement (none) compared to the $100 top up per year of most Canadian cell providers.

Calls are very reasonably priced, $0.22 per minute Canada wide (again, most Canadian prepaid providers easily ask twice that).
Text $0.15 (Canadian providers: $0.50 per text)
Data is $0.37 per MB. If you don't want a data add-on with a fixed amount, the only prepaid provider Telus offers ppu data of $2.00 per MB. Granted, that is not in 100kb increments like Piranha.

I can't fault Piranha in any way though and of all the prepaid international SIMs I tried, it's the only one I kept. For the 2 countries I frequent regularly (USA and NL), I bought a local SIM (T-Mobile and Simyo, respectively) and in Canada I use Koodo prepaid.

But for extremely light users such as said relative, Piranha is actually a good local alternative here!