SeekingInsight,
I am glad you are thinking about nursing and I am biased but think it is a great career!

You already have many of the nursing prereqs and you might find it useful to make an appointment at a university or college in your area with someone in the nursing department and have them go over your transcripts with you. They should be able to help you realistically assess how much time it would take you to complete the BSN program or if you'd be better off to get your BS in biology and then apply to an accelerated program....I don't think you would but find out for sure.
This is what I did when I decided to go to nursing school but I already had a BA in psychology. I didn't know that accelerated BSN programs existed and the person I met with at a private college kindly pointed me to the local university that had the accelerated program. You can probably get your answers from the schools of nursing that you are considering so I'd start there. Good luck!