I think in her case it's because it has been completely useless from a practical standpoint. With the exception of college courses and a single trip to France in 1968 she hasn't "used" it a single time. I think living the last 15 years in California (and now southern California) is what prompted her to make the "Spanish would be preferrable" comment... at least you could use it from time to time - or at very least be able to understand people around you.
I never exactly concerned myself with the practicality of a language when I was learning it. Hence why I would learn French over Spanish.