As much as we love and advocate vintage machines your best bet would be a new one given the distances involved.
Shipping and not being able to show how to use it yourself are deal breakers on vintage machines. Do try to get her one from an actual sewing machine dealer instead of a big box store though. Maybe they have a good used machine in on trade? It can't hurt to ask. That way it will be easier to get any repair work or adjustments that may be needed in the future done.
Rodney