Hmm, I don't know the exact reasons for her wanting to go into medicine but It sounds like to me that she would benefit more from looking into the RN --> NP or PA route.
As she just turned 50, even in the case that she was accepted, she wouldn't be a full-fledged physician (attending) until around 60. Give or take a few years depending on what specialty. If that is something that she is knowing going into then power to her but at this point, it's a cost/benefit analysis. (I've heard some med schools factor in how many expected years of practice when admitting students as well but don't quote me haha)
If she is interested because of the allopathic medicine philosophy--> PA. If she is interested more in patient care and well-being --> NP. Since she already has a foot in the latter, I would suggest she save herself the stress of going through another cycle of "what if" "what if not." Mind you, all of these are all respectable careers and should not be seen hierarchically. They were simply created to play different roles in healthcare.
That said, two things to consider:
1) If she rejects this acceptance into nursing school, she may be closing the door on that profession in the future. It is difficult to convince an ADCOM if you apply later that you are genuinely interested in nursing since you've given it up for another field.
2) Going to the level of NP, depending on the state, you have a similar (but importantly, not the same) scope of practice as a primary care physician. Some states even allow autonomy I think (do your own research)
I hope the best to your mother and respect you looking out for her :] Good to see in this day and age.
Edit: forgot to add that PA is usually 2-3 years and RN --> 1-2 accelerated and NP is 1-2 years post working in a hospital as an RN. I also don't know if an MSN is eligible for an NP.
