I applaud you, for attending school as a single mom. My husband and I are on only his income, have 2 sons and one on the way, so I understand how things are tight from week to week.
From what I understand, ADN and BSN pay can differentiate from 25 to 50 cents, if any.
If I were you, understanding how it is to struggle and sacrafice (we live on 1600 for the 4 and one on the way, to pay bills, groceries, etc), I would get your ADN. Pass the NCLEX, get a job as a RN. Then you can fast track (online/night) for your BSN in a year. You more than likely will qualify for a pell grant, which would pay for your schooling/books. You would have income coming in (more than you probably have now), and still be able to go to school.
Here is a link to a school in Tulsa:
It explains the RN to BSN program. You can check out other schools around you that also have this option. From what this one looks like, some of the work is done online, then your class lectures. And if you are already an RN, your hospital will more than likey work with you on a school schedule, and may even offer tuition assistance!
That's what I would do, and am in the process of doing right now. Congrats and good luck to you!