If she does not pick it up it should be returned to you (but then this is France, their PO does not have the best rep for honesty.)
Canada Post can and may charge you for return postage, especially if it was shipped surface.
I agree, don't refund unless you get the product back with no further charges to you. Even then, deduct the cost of shipping and your fees, as it's too late to get them back now. Hope you didn't leave feedback first.
Ann