Considering comparable mileage upgrades, this one really is a no brainer!
AS Domestic Saver Coach vs. Saver First: 25K difference
AS Mileage upgrade on paid domestic ticket (After you've paid up to an eligible fare class) r/t: 30K
And you can fly half way around the world in international business class for a comparable number of miles?!?!?!? Especially for her traveling from DC.
You made a fine choice! Enjoy your trip!