One issue with the medical field that I don't think has been mentioned is the schedule AFTER the schooling is completed...not to say there aren't nursing positions out there with "normal" hours, but most LPNs, techs, or RNs that I know spend quite a bit of time on second, third, or rotating shifts - even after you're trained, licensed, and employed, that schedule might not mix well with the single-parent issue. Maybe its not a problem, maybe it is...but something to keep in mind.
Also, you have to consider where you live. Some have said "IT is always hiring," others "There are no IT jobs." Same applies to nursing, sales, and everything in between. Where I am (NE Ohio), the tech industry is wide open as is accounting (another field which you can get trained in online, if numbers suit your fancy). Plenty of nursing jobs around here, too, but there's also a lot of competition (many, many nursing students in Ohio, coming out of a number of reputable schools). Good luck finding a good job in sales, distribution, or a million other things around here, though.
I'd expect the situation to be different in other communities. What's true in NE Ohio isn't necessarily true in the communities where other BoBers live, including out in your area (Eastern PA, I think?).
You might want to jump on the online job posting sites and pick up a few Sunday newspapers and look through the classifieds. Unless you're planning/willing to relocate, you might want to start by asking:
--What's hiring in my area?
--Is that field growing (or at least not shrinking)?
--Even though I'm not "following a dream" per se, is this a field I can see myself in long-term?
But then this is coming from a guy who makes his living in a field that is entirely unfulfilling and unrelated to the degrees I've earned, so don't put too much stock in what I have to say.