Maybe her address listed with Paypal and Ebay is England, but she wants you to ship to Canada.

I'd email her and ask, reminding her about her question.

I've had international buyers have me ship to friends of theirs in the US, and then they get their items from them, especially if they know a student studying here,
that can bring the item home with them.

I'd check out all scenarios before just refunding and cancelling her purchase.