If I recall correctly, last year fewer than 20% of Equity members booked any work, and the average annual pay of those who did was under $8,000, so clearly even most professional actors earn the bulk of their income doing something else. I think it is very rational to give thought to survival skills, and nursing sounds like it might be a good one.
Also, double majoring in 4 years is possible in some schools. I know kids in D’s program who graduated in June and have already taken or will soon take the LSAT and MCAT. And those same kids are already booking solid MT contracts, so splitting their focus in college doesn’t seem to have limited their performing skills.
By the way, I don’t consider facing the financial realities of the profession as being negative since the rubber will eventually hit the road for most actors whether they plan for it or not, and those who survive long term will likely need a flexible skill set that extends beyond performing.