Okay, new thoughts based upon this new information:
I didn't realize you already have one bachelor's degree -- this is very good because it means you have all your general degree requirements. You may need an odd class or two, but you're much further down the road than I had realized. However, I think you're viewing everything in a best-case situation: You're planning on studying while nursing the baby (isn't that a time to talk to the child, build a bond with the baby?), assuming you'll be able to go to Clinical hours while your older kids are at school, figuring day car for the others will just appear ... some of these things will probably work out, but hoping for them all is unrealistic.
And then after this -- I think another poster chose her words well -- soul-sucking couple of years are finished, you're planning to work part-time 'til the kids are all established in school? To borrow from another poster, I don't see the ROI. If you succeed with this plan, your kids will suffer because you won't "be there" during those all-important first years. In general, I'm very supportive of education and furthering your skills, and I think nursing is a great career ... but I don't see your plans as realistic.
Is my daughter's nursing program Draconian? I don't know -- I have no frame of reference; I only know what she tells me about this one program. However, I do know that she is learning and progressing, and I have no doubt she'll pass the NCLEX on her first try. I asked her if anyone in her program has children, and she looked at me like I had two heads. She says one girl was married last summer, and they did have one man in the group who was married/had one child, but he dropped out -- she doesn't know why; she sort of thinks it was about money.
Here are a couple options I see as more possible for the mother of four kids, one of them a newborn:
1. Look into becoming a CNA. If you have any experience in nursing, you can "challenge" the test and take it without taking any classes -- you'd want to get a book with which to review. The test costs $110 in my state, and you're licensed for two years /if you work 8 hours during that two years, you can ask for your license to be renewed. If you take the class to become a CNA2, you'll make more money. CNAs can work in nursing homes or home health (and you said that in Florida the need for elder-care is huge) or can work in hospitals. It's hard physical work: Lots of bathing people, feeding people. But you could realistically -- after recovering from childbirth -- start working and bringing money in before Christmas. You could work night shifts, as someone else suggested, so you and your husband could tag-team the childcare. My daughter has worked as a CNA in a couple places, and she earns $10-12/hour. No, that's not nearly what an RN earns, but you wouldn't need to go through the years of classes and Clinicals, and you could start bringing in money SOON for your family -- without any additional student loans. And you could attack nursing school once your children are all older, in school, doing their own laundry, and so forth. Plus, you'd begin with a wealth of practical knowledge.
2. Look into substitute teaching. You're qualified NOW. In my state you only need a high school diploma and a criminal background check. Since you have a bachelor's degree, you'd -- in my state -- make about $75/day. The beauty of this job is that you'd work school hours, and you'd never need to search for child care for teacher workdays /summers (I'm a teacher, and not needing care on these days saved us immeasureable money and stress -- it's one of the reasons teachers put up with the low pay). You would have the option to say, "No, I can't work on Monday; I'm going to my son's class party, but please do call me next time." Our best couple subs work as many days as they want; literally, when we know we have to be out, we call them ASAP, and pretty frequently they say, "I'm sorry, but I've already promised Mrs. Smith for that day." My favorite sub has a personal goal to work 12 days every month -- that's her personal "sweet spot" between having a check at the end of the month and being available for her middle school son. She never, ever fails to work her goal of 12, and she often works more than she wants just because she doesn't want to say no. One intangible benefit: You'd know all the teachers in your children's school, which is a help to them in their education; my own kids always had the best teachers, and being in constant communication with them was a big plus to them -- especially my rowdy youngest. And, of course, two big benefits: 1) the hours are consistent, and 2) when the school bell rings, you're done -- no homework for you, you belong to your family.
3. You have a degree in Psychology. A bachelor's in Psych doesn't open a whole lot of doors for you, but you could get a job as a Social Worker now. This is a hard-to-fill job, and it doesn't pay well, but it does come with state benefits and a state pension. State pensions are stable, and even if you don't intend to put in a full 30 years, you might be glad of a small pension later. People who enter this field tend to start in Welfare benefits, which is a 9-5 type job, and you wouldn't bring any work home; thus, when you come home, you'd belong to your family.