When you call AC, you may also use the fact that the is coming from US and it happends that the flights from EWR (if she is leaving from there) are `often`cancelled for various reasons. May be she will be able to go trough YUL and take the AC870 with a real J class. Or, if they say no, check the load of the flight on KVS before going to the airport. If the YYZ-CDG flight is quite full and there is space from YUL, offer AC to change your route, that may help their Canadian gate agents in YYZ, and she will enjoy a real J class.

But to be honest, she will survive in Club Class.

Bonne chance!

david