I would advise you to think very carefully and talk to as many nurses as possible before you make a decision. I am 51 and have had several careers. I have a CPA, MBA, worked in accounting for many years and have also taught high school for 5 years. I was not satisfied doing all these things and had always dreamed of being a nurse. I graduated May of 2011 with my BSN. Working as a nurse has been a big disappointment to me. It is very stressful and at many times feels like an impossible situation. I wanted to help and serve people (which is why I found accounting so unsatisfying) however, nursing is so busy and you are pulled in so many directions that at the end of the day, I still didn't feel I was providing the kind of care I wanted for my patients because of time constraints. The pay is also very poor. I was making more teaching high school (which is hard too, but with much better hours) than working 12 hour shifts as a nurse. To top it off, after working 7-8 months my knee started hurting, I discovered I have bone on bone arthritis and the only solution is knee replacement which I am not ready for. I have just resigned my med surg nursing position because it is too painful to work 12 hour shifts. I know there are other nursing jobs out there with better hours, but I have less than 1 year experience and right now I just can't bring myself to look.
Anyway, I don't mean to be all negative, I just want to make sure you know about some of the possiblities before you make this decision. You also might want to consider volunteering at a local hospital in the evenings or weekends. This would let you become more familiar with the environment and help make your decision. You might find that as a volunteer you can do more to truly help and serve people without all the other constraints. If you decide nursing is what you still want, then go for it.
Best of luck with whatever you decide!