Mrs. Luthor - No, it isn't mandatory to take Spanish here in the US.
I'm a child of '82 and never took a foreign language before 9th grade. My elementary school did teach Latin, but the teacher retired the year before I would have started.
In high school, I had to take Latin as an Honor's Student and choose a modern language - Spanish, Italian, or French (I chose French). In college, I had my choice of languages (and again took French).
However, I can see Lois choosing to take a foreign language in school, being the overachiever she was. She loves a challenge, and maybe she had dreams of working for a paper in Paris before landing an internship/position at the Planet.
Just as an example.
